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Additions to the NASA Aeronautics and Space Database as of 10/27/2011
20110016167 NASA Johnson Space Center, Houston, TX, United States
Select Astronaut Observations and Highlights of Space Shuttle Program Payloads and Experiments. Supplement to Wings in Orbit: Scientific and Engineering Legacies of the Space Shuttle (NASA/SP-2010-3409)
Lane, Helen; Lulla, Kamlesh; Miller, Jason; October 2011; In English
Report No.(s): NASA/TM-2011-216150; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016167
This document was compiled to provide selected highlights of the science and engineering payloads, experiments, engineering and scientific tests, and other technical activities that were carried out during the Space Shuttle era. It is very important to note that this TM highlights selected payloads and experiments to offer glimpses into the intensive scientific and engineering initiatives throughout the Space Shuttle Program. While this document is quite detailed and highly informative, it is neither comprehensive nor encyclopedic. The intention is to give readers an overview of the shuttle science and engineering payloads. In addition, selected personal observations were provided by a handful of astronauts. The data on the Space Shuttle flights highlighted in this document are in chronological order by date(s) of the mission. The summaries are high-level descriptions of the experiments/engineering tests, etc.
Author
SPACE SHUTTLE PAYLOADS; SPACE SHUTTLES; SPACE TRANSPORTATION SYSTEM FLIGHTS; ASTRONAUTS; MICROGRAVITY
Additions to the NASA Aeronautics and Space Database as of 11/01/2011
20110016323 ENSCO, Inc., Cocoa Beach, FL, United States
Situational Lightning Climatologies for Central Florida: Phase V
Bauman, William H., III; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNK06MA70C
Report No.(s): NASA/CR-2011-216303; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016323
The AMU added three years of data to the POR from the previous work resulting in a 22-year POR for the warm season months from 1989-2010. In addition to the flow regime stratification, moisture and stability stratifications were added to separate more active from less active lighting days within the same flow regime. The parameters used for moisture and stability stratifications were PWAT and TI which were derived from sounding data at four Florida radiosonde sites. Lightning data consisted of NLDN CG lightning flashes within 30 NM of each airfield. The AMU increased the number of airfields from nine to thirty-six which included the SLF, CCAFS, PAFB and thirty-three airfields across Florida. The NWS MLB requested the AMU calculate lightning climatologies for additional airfields that they support as a backup to NWS TBW which was then expanded to include airfields supported by NWS JAX and NWS MFL. The updated climatologies of lightning probabilities are based on revised synoptic-scale flow regimes over the Florida peninsula (Lambert 2007) for 5-, 10-, 20- and 30-NM radius range rings around the thirty-six airfields in 1-, 3- and 6-hour increments. The lightning, flow regime, moisture and stability data were processed in S-PLUS software using scripts written by the AMU to automate much of the data processing. The S-PLUS data files were exported to Excel to allow the files to be combined in Excel Workbooks for easier data handling and to create the tables and charts for the Gill. The AMU revised the Gill developed in the previous phase (Bauman 2009) with the new data and provided users with an updated HTML tool to display and manipulate the data and corresponding charts. The tool can be used with most web browsers and is computer operating system independent. The AMU delivered two Gills - one with just the PWAT stratification and one with both the PWAT and TI stratifications due to insufficient data in some of the PWATITI stratification combinations. This will allow the forecasters to choose a moisture-only or moisture/stability stratification depending on the flow regime and available data.
Author
LIGHTNING; DOCUMENT MARKUP LANGUAGES; CLIMATOLOGY; STRATIFICATION; PROBABILITY THEORY; MOISTURE; STRATIFIED FLOW; RADIOSONDES; FLOW STABILITY
20110016325 ENSCO, Inc., Cocoa Beach, FL, United States
MesoNAM Verification Phase II
Watson, Leela R.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNK06MA70C
Report No.(s): NASA/CR-2011-216304; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016325
The 45th Weather Squadron Launch Weather Officers use the 12-km resolution North American Mesoscale model (MesoNAM) forecasts to support launch weather operations. In Phase I, the performance of the model at KSC/CCAFS was measured objectively by conducting a detailed statistical analysis of model output compared to observed values. The objective analysis compared the MesoNAM forecast winds, temperature, and dew point to the observed values from the sensors in the KSC/CCAFS wind tower network. In Phase II, the AMU modified the current tool by adding an additional 15 months of model output to the database and recalculating the verification statistics. The bias, standard deviation of bias, Root Mean Square Error, and Hypothesis test for bias were calculated to verify the performance of the model. The results indicated that the accuracy decreased as the forecast progressed, there was a diurnal signal in temperature with a cool bias during the late night and a warm bias during the afternoon, and there was a diurnal signal in dewpoint temperature with a low bias during the afternoon and a high bias during the late night.
Author
MESOMETEOROLOGY; MESOSCALE PHENOMENA; SPACE SHUTTLES; NUMERICAL WEATHER FORECASTING; CLIMATOLOGY
20110016348 ENSCO, Inc., Cocoa Beach, FL, United States
Peak Wind Forecasts for the Launch-Critical Wind Towers on Kennedy Space Center/Cape Canaveral Air Force Station, Phase IV
Crawford, Winifred; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNK06MA70C
Report No.(s): NASA/CR-2011-216305; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016348
This final report describes the development of a peak wind forecast tool to assist forecasters in determining the probability of violating launch commit criteria (LCC) at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The peak winds arc an important forecast clement for both the Space Shuttle and Expendable Launch Vehicle (ELV) programs. The LCC define specific peak wind thresholds for each launch operation that cannot be exceeded in order to ensure the safety of the vehicle. The 45th Weather Squadron (45 WS) has found that peak winds are a challenging parameter to forecast, particularly in the cool season months of October through April. Based on the importance of forecasting peak winds, the 45 WS tasked the Applied Meteorology Unit (AMU) to update the statistics in the current peak-wind forecast tool to assist in forecasting LCC violations. The tool includes onshore and offshore flow climatologies of the 5-minute mean and peak winds and probability distributions of the peak winds as a function of the 5-minute mean wind speeds.
Author
LAUNCH VEHICLES; WIND (METEOROLOGY); WEATHER FORECASTING; CLIMATOLOGY; TOWERS; LAUNCHING PADS; PROBABILITY THEORY
Additions to the NASA Aeronautics and Space Database as of 11/03/2011
20110016415 NASA Langley Research Center, Hampton, VA, United States
Review of Nuclear Physics Experiments for Space Radiation
Norbury, John W.; Miller, Jack; Adamczyk, Anne M.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; Blattnig, Steve R.; Norman, Ryan B.; Guetersloh, Stephen B.; Zeitlin, Cary J.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 651549.02.07.01
Report No.(s): NASA/TP-2011-217179; L-20067; NF1676L-13441; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016415
Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made.
Author
NUCLEAR PHYSICS; RADIATION PROTECTION; ASTRONAUTS; EXTRATERRESTRIAL RADIATION; PROJECTILES
Additions to the NASA Aeronautics and Space Database as of 11/04/2011
20110016498 NASA Langley Research Center, Hampton, VA, United States
Comparison of the Booster Interface Temperature in Stainless Steel (SS) V-Channel versus the Aluminum (Al) Y-Channel Primer Chamber Assemblies (PCAs) Volume 1 Technical Assessment Report
Garcia, Roberto; Saulsberry, Regor L.; October 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 869021.05.07.01.10
Report No.(s): NASA/TM-2011-217182/VOL1; NESC-RP-09-00596; L-20081; NF1676L-13623; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016498
NASA's Technical Fellow for Propulsion, requested a technical assessment of the performance improvement achieved by the introduction of the stainless steel (SS) V-channel compared to the aluminum (Al) Y-channel Primer Chamber Assembly (PCA) design. The SS V-channel PCA was developed for NASA's Mars Science Laboratory (MSL) Project. The principle focus of the assessment was to measure the transient temperature at the booster interface with both designs. This document contains the findings of the assessment.
Author
ALUMINUM; STAINLESS STEELS; TEMPERATURE MEASUREMENT; PYROTECHNICS; BOOSTERS (EXPLOSIVES); CONTROL VALVES; PRIMERS (EXPLOSIVES); COMPUTATIONAL FLUID DYNAMICS; RESONANCE; FLOW CHAMBERS
20110016500 NASA Langley Research Center, Hampton, VA, United States
Comparison of the Booster Interface Temperature in Stainless Steel (SS) V-Channel Versus the Aluminum (Al) Y-Channel Primer Chamber Assemblies (PCAs) Volume 2 Appendices
Garcia, Roberto; Saulsberry, Regor L.; October 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-217182/VOL2; NESC-RP-09-00596; L-20082; NF1676L-13624; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016500
NASA's Technical Fellow for Propulsion, requested a technical assessment of the performance improvement achieved by the introduction of the stainless steel (SS) V-channel compared to the aluminum (Al) Y-channel Primer Chamber Assembly (PCA) design. The SS V-channel PCA was developed for NASA's Mars Science Laboratory (MSL) Project. The principle focus of the assessment was to measure the transient temperature at the booster interface with both designs. This document contains the Appendices to the Volume I main report.
Author
STAINLESS STEELS; ALUMINUM; CONTROL VALVES; PYROTECHNICS; BOOSTERS (EXPLOSIVES); PRIMERS (EXPLOSIVES); COMPUTATIONAL FLUID DYNAMICS; RESONANCE; FLOW CHAMBERS
20110016508 NASA Langley Research Center, Hampton, VA, United States
Design, Optimization and Evaluation of Integrally Stiffened Al 7050 Panel with Curved Stiffeners
Slemp, Wesley C. H.; Bird, R. Keith; Kapania, Rakesh K.; Havens, David; Norris, Ashley; Olliffe, Robert; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.07.15.15
Report No.(s): NASA/TP-2011-217178; L-20075; NF1676L-13526; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016508
A curvilinear stiffened panel was designed, manufactured, and tested in the Combined Load Test Fixture at NASA Langley Research Center. The panel was optimized for minimum mass subjected to constraints on buckling load, yielding, and crippling or local stiffener failure using a new analysis tool named EBF3PanelOpt. The panel was designed for a combined compression-shear loading configuration that is a realistic load case for a typical aircraft wing panel. The panel was loaded beyond buckling and strains and out-of-plane displacements were measured. The experimental data were compared with the strains and out-of-plane deflections from a high fidelity nonlinear finite element analysis and linear elastic finite element analysis of the panel/test-fixture assembly. The numerical results indicated that the panel buckled at the linearly elastic buckling eigenvalue predicted for the panel/test-fixture assembly. The experimental strains prior to buckling compared well with both the linear and nonlinear finite element model.
Author
BUCKLING; FINITE ELEMENT METHOD; DESIGN OPTIMIZATION; LOAD TESTS; ELASTIC BUCKLING; WING PANELS; FIXTURES; DEFLECTION; LOADS (FORCES)
20110016512 Jacobs Technology, Inc., Cleveland, OH, United States
Liquid Methane Conditioning Capabilities Developed at the NASA Glenn Research Center's Small Multi- Purpose Research Facility (SMiRF) for Accelerated Lunar Surface Storage Thermal Testing
Bamberger, Helmut H.; Robinson, R. Craig; Jurns, John M.; Grasl, Steven J.; September 2011; In English; JANNAF 2010, 3-7 May 2010, Colorado Springs, CO, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC05CA95CWBS 095240.04.03.03.03.03
Report No.(s): NASA/CR-2011-216745; E-17322; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016512
Glenn Research Center s Creek Road Cryogenic Complex, Small Multi-Purpose Research Facility (SMiRF) recently completed validation / checkout testing of a new liquid methane delivery system and liquid methane (LCH4) conditioning system. Facility checkout validation was conducted in preparation for a series of passive thermal control technology tests planned at SMiRF in FY10 using a flight-like propellant tank at simulated thermal environments from 140 to 350K. These tests will validate models and provide high quality data to support consideration of LCH4/LO2 propellant combination option for a lunar or planetary ascent stage.An infrastructure has been put in place which will support testing of large amounts of liquid methane at SMiRF. Extensive modifications were made to the test facility s existing liquid hydrogen system for compatibility with liquid methane. Also, a new liquid methane fluid conditioning system will enable liquid methane to be quickly densified (sub-cooled below normal boiling point) and to be quickly reheated to saturation conditions between 92 and 140 K. Fluid temperatures can be quickly adjusted to compress the overall test duration. A detailed trade study was conducted to determine an appropriate technique to liquid conditioning with regard to the SMiRF facility s existing infrastructure. In addition, a completely new roadable dewar has been procured for transportation and temporary storage of liquid methane. A new spherical, flight-representative tank has also been fabricated for integration into the vacuum chamber at SMiRF. The addition of this system to SMiRF marks the first time a large-scale liquid methane propellant test capability has been realized at Glenn.This work supports the Cryogenic Fluid Management Project being conducted under the auspices of the Exploration Technology Development Program, providing focused cryogenic fluid management technology efforts to support NASA s future robotic or human exploration missions.
Author
LIQUEFIED GASES; CRYOGENIC FLUIDS; PROPELLANT TESTS; THERMAL ENVIRONMENTS; VACUUM CHAMBERS; LIQUID HYDROGEN; METHANE; CRYOGENICS; FLUID MANAGEMENT; RESEARCH FACILITIES
Additions to the NASA Aeronautics and Space Database as of 11/07/2011
20110016522 NASA Glenn Research Center, Cleveland, OH, United States
Oxide Scales Formed on NiTi and NiPtTi Shape Memory Alloys
Smialek, James L.; Garg, Anita; Rogers, Richard B.; Noebe, Ronald D.; September 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-217096; E-17748; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016522
Ni-49Ti and Ni-30Pt-50Ti (at.%) shape memory alloys were oxidized isothermally in air over the temperature range of 500 to 900 C. The microstructure, composition, and phase content of the scales were studied by SEM, EDS, XRD, and metallography. Extensive plan view SEM/EDS identified various features of intact or spalled scale surfaces. The outer surface of the scale was a relatively pure TiO2 rutile structure, typified by a distinct highly striated and faceted crystal morphology. Crystal size increased significantly with temperature. Spalled regions exhibited some porosity and less distinct features. More detailed information was obtained by correlation of SEM/EDS studies of 700 C/100 hr cross-sections with XRD analyses of serial or taper-polishing of plan surfaces. Overall, multiple layers exhibited graded mixtures of NiO, TiO2, NiTiO3, Ni(Ti) or Pt(Ni,Ti) metal dispersoids, Ni3Ti or Pt3Ti depletion zones, and substrate, in that order. The NiTi alloy contained a 3 at.% Fe impurity that appeared in embedded localized Fe-Ti-rich oxides, while the NiPtTi alloy contained a 2 v/o dispersion of TiC that appeared in lower layers. The oxidation kinetics of both alloys (in a previous report) indicated parabolic growth and an activation energy (250 kJ/mole) near those reported in other Ti and NiTi studies. This is generally consistent with TiO2 existing as the primary scale constituent, as described here.
Author
NICKEL ALLOYS; METALLOGRAPHY; SHAPE MEMORY ALLOYS; REACTION KINETICS; POROSITY; OXIDATION; ISOTHERMAL PROCESSES; TITANIUM ALLOYS; TITANIUM OXIDES; CRYSTAL MORPHOLOGY; BINARY ALLOYS
20110016523 NASA Glenn Research Center, Cleveland, OH, United States
Performance of a Kilowatt-Class Stirling Power Conversion System in a Thermodynamically Coupled Configuration
Geng, Steven M.; Briggs, Maxwell H.; Hervol, David S.; September 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 463169.04.03.01.02
Report No.(s): NASA/TM-2011-217098; NETS-2011-3269; E-14604; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016523
A pair of 1-kWe free-piston Stirling power convertors has been modified into a thermodynamically coupled configuration, and performance map testing has been completed. This is the same configuration planned for the full-scale 12-kWe power conversion unit (PCU) that will be used in the Fission Power System Technology Demonstration Unit (TDU). The 1-kWe convertors were operated over a range of conditions to evaluate the effects of thermodynamic coupling on convertor performance and to identify any possible control challenges. The thermodynamically coupled convertor showed no measureable difference in performance from the baseline data collected when the engines were separate, and no major control issues were encountered during operation. The results of this test are guiding controller development and instrumentation selection for the TDU.
Author
THERMODYNAMIC COUPLING; STIRLING CYCLE; FISSION; PISTON ENGINES
20110016524 NASA Glenn Research Center, Cleveland, OH, United States
Resilient and Corrosion-Proof Rolling Element Bearings Made from Superelastic Ni-Ti Alloys for Aerospace Mechanism Applications
DellaCorte, Christopher; Noebe, Ronald D.; Stanford, Malcolm; Padula, Santo A.; August 2011; In English; ASTM 2011 Symposium on Rolling Element Bearings, 13-15 Aprl. 2011, Los Angeles, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.03.04
Report No.(s): NASA/TM-2011-217105; E-17678-1; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016524
Mechanical components (bearings, gears, mechanisms) typically utilize hard materials to minimize wear and attain long life. In such components, heavily loaded contact points (e.g., meshing gear teeth, bearing ball-raceway contacts) experience high contact stresses. The combination of high hardness, heavy loads and high elastic modulus often leads to damaging contact stress. In addition, mechanical component materials, such as tool steel or silicon nitride exhibit limited recoverable strain (typically less than 1 percent). These material attributes can lead to Brinell damage (e.g., denting) particularly during transient overload events such as shock impacts that occur during the launching of space vehicles or the landing of aircraft. In this paper, a superelastic alloy, 60NiTi, is considered for rolling element bearing applications. A series of Rockwell and Brinell hardness, compressive strength, fatigue and tribology tests are conducted and reported. The combination of high hardness, moderate elastic modulus, large recoverable strain, low density, and intrinsic corrosion immunity provide a path to bearings largely impervious to shock load damage. It is anticipated that bearings and components made from alloys with such attributes can alleviate many problems encountered in advanced aerospace applications.
Author
COMPRESSIVE STRENGTH; FATIGUE TESTS; LOADS (FORCES); GEARS; BEARINGS; SHOCK LOADS; HARDNESS TESTS; MODULUS OF ELASTICITY; ROCKWELL HARDNESS
20110016525 NASA Glenn Research Center, Cleveland, OH, United States
Comparison of Adhesion and Retention Forces for Two Candidate Docking Seal Elastomers
Hartzler, Brad D.; Panickar, Marta B.; Wasowski, Janice L.; Daniels, Christopher C.; September 2011; In English; 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 4-7 Apr. 2011, Denver, CO, United States; Original contains color illustrations
Contract(s)/Grant(s): NNC08CA35CWBS 644423.06.31.04.01.03.72
Report No.(s): NASA/CR-2011-217109; AIAA Paper-2011-2158; E-17785; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016525
To successfully mate two pressurized vehicles or structures in space, advanced seals are required at the interface to prevent the loss of breathable air to the vacuum of space. A critical part of the development testing of candidate seal designs was a verification of the integrity of the retaining mechanism that holds the silicone seal component to the structure. Failure to retain the elastomer seal during flight could liberate seal material in the event of high adhesive loads during undocking. This work presents an investigation of the force required to separate the elastomer from its metal counter-face surface during simulated undocking as well as a comparison to that force which was necessary to destructively remove the elastomer from its retaining device. Two silicone elastomers, Wacker 007-49524 and Esterline ELASA-401, were evaluated. During the course of the investigation, modifications were made to the retaining devices to determine if the modifications improved the force needed to destructively remove the seal. The tests were completed at the expected operating temperatures of -50, +23, and +75 C. Under the conditions investigated, the comparison indicated that the adhesion between the elastomer and the metal counter-face was significantly less than the force needed to forcibly remove the elastomer seal from its retainer, and no failure would be expected.
Author
ELASTOMERS; SPACECRAFT DOCKING; ADHESION; ADHESIVES; VACUUM; SILICONES; LOADS (FORCES)
20110016526 NASA Glenn Research Center, Cleveland, OH, United States
Atmospheric and Soil Carbon and Halophytes
Hendricks, Robert C.; Bushnell, Dennis M.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.16.03
Report No.(s): NASA/TM-2011-217132; E-17204-2; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016526
World population is anticipated to grow 40% within 40-50 years (2008 baseline) with unprecedented demands for energy, food, freshwater, and clean environments. At 43% of the total landmass, exploiting the Earth's arid and semi-arid lands becomes a matter of necessity. Compared with glycophyte agriculture, we view seawater and brackish water halophyte saline agriculture in its nascent stage and see the need to explore and farm on a massive scale. Halophyte farming costs should be the same as glycophyte cellulosic biomass farming; processing for cellulosic matter should also be applicable. Halophyte life cycle analyses (LCA) within the fueling debate are incomplete, yet glycophyte LCA favors biomass fueling. The Biomass Revolution is in progress. The capacity, cost, and logistics required for biomass replacement of petroleum-based fuels, however, will require all feedstock sources and regional cooperative productivity, technical investments, and both the participation and cooperation of the American farmer and global farm community.
Author
ATMOSPHERIC CHEMISTRY; SOILS; WATER RESOURCES; CARBON CYCLE; ARID LANDS
20110016527 NASA Glenn Research Center, Cleveland, OH, United States; NASA Glenn Research Center, Cleveland, OH, United States
Progress in Materials and Component Development for Advanced Lithium-ion Cells for NASA's Exploration Missions
Reid, Concha, M.; Reid, Concha M.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 152964.04.01.01.04.03
Report No.(s): NASA/TM-2011-217209; E-17669; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016527
Vehicles and stand-alone power systems that enable the next generation of human missions to the Moon will require energy storage systems that are safer, lighter, and more compact than current state-of-the- art (SOA) aerospace quality lithium-ion (Li-ion) batteries. NASA is developing advanced Li-ion cells to enable or enhance the power systems for the Altair Lunar Lander, Extravehicular Activities spacesuit, and rovers and portable utility pallets for Lunar Surface Systems. Advanced, high-performing materials are required to provide component-level performance that can offer the required gains at the integrated cell level. Although there is still a significant amount of work yet to be done, the present state of development activities has resulted in the synthesis of promising materials that approach the ultimate performance goals. This report on interim progress of the development efforts will elaborate on the challenges of the development activities, proposed strategies to overcome technical issues, and present performance of materials and cell components.
Author
COMPONENT RELIABILITY; LITHIUM; NASA SPACE PROGRAMS; LUNAR SURFACE; METAL IONS; ELECTROCHEMICAL CELLS
20110016528 NASA Glenn Research Center, Cleveland, OH, United States
Annular MHD Physics for Turbojet Energy Bypass
Schneider, Steven J.; September 2011; In English; 17th AIAA International Space Planes and Hypersonics Systems Conference, 11-14 Apr. 2011, San Francisco, CA, United States; Original contains color illustrations
Report No.(s): NASA/TM-2011-217210; AIAA Paper-2011-2230; E-17889; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016528
The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).
Author
BYPASSES; ENTHALPY; HALL GENERATORS; MAGNETOHYDRODYNAMIC GENERATORS; MAGNETOHYDRODYNAMICS; TURBOJET ENGINES
20110016529 NASA Glenn Research Center, Cleveland, OH, United States
Space Propulsion Research Facility (B-2): An Innovative, Multi-Purpose Test Facility
Hill, Gerald M.; Weaver, Harold F.; Kudlac, Maureen T.; Maloney, Christian T.; Evans, Richard K.; September 2011; In English; FROM 26th Aerospace Testing Seminar, 29-30 Mar. 2011, Manhattan Beach, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 750271.01.03
Report No.(s): NASA/TM-2011-217007; E-17670; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016529
The Space Propulsion Research Facility, commonly referred to as B-2, is designed to hot fire rocket engines or upper stage launch vehicles with up to 890,000 N force (200,000 lb force), after environmental conditioning of the test article in simulated thermal vacuum space environment. As NASA s third largest thermal vacuum facility, and the largest designed to store and transfer large quantities of propellant, it is uniquely suited to support developmental testing associated with large lightweight structures and Cryogenic Fluid Management (CFM) systems, as well as non-traditional propulsion test programs such as Electric and In-Space propulsion. B-2 has undergone refurbishment of key subsystems to support the NASA s future test needs, including data acquisition and controls, vacuum, and propellant systems. This paper details the modernization efforts at B-2 to support the Nation s thermal vacuum/propellant test capabilities, the unique design considerations implemented for efficient operations and maintenance, and ultimately to reduce test costs.
Author
RESEARCH FACILITIES; ENVIRONMENTAL TESTS; THERMAL VACUUM TESTS; VACUUM SYSTEMS; PROPELLANT TESTS; MANAGEMENT SYSTEMS; FLUID MANAGEMENT; TEST FACILITIES; CONTROL SYSTEMS DESIGN; CRYOGENIC FLUIDS; ROCKET ENGINES
20110016531 NASA Glenn Research Center, Cleveland, OH, United States
Improving Data Collection and Analysis Interface for the Data Acquisition Software of the Spin Laboratory at NASA Glenn Research Center
Abdul-Aziz, Ali; Curatolo, Ben S.; Woike, Mark R.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 284848.02.03.02.01
Report No.(s): NASA/TM-2011-217214; E-17895; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016531
In jet engines, turbines spin at high rotational speeds. The forces generated from these high speeds make the rotating components of the turbines susceptible to developing cracks that can lead to major engine failures. The current inspection technologies only allow periodic examinations to check for cracks and other anomalies due to the requirements involved, which often necessitate entire engine disassembly. Also, many of these technologies cannot detect cracks that are below the surface or closed when the crack is at rest. Therefore, to overcome these limitations, efforts at NASA Glenn Research Center are underway to develop techniques and algorithms to detect cracks in rotating engine components. As a part of these activities, a high-precision spin laboratory is being utilized to expand and conduct highly specialized tests to develop methodologies that can assist in detecting predetermined cracks in a rotating turbine engine rotor. This paper discusses the various features involved in the ongoing testing at the spin laboratory and elaborates on its functionality and on the supporting data system tools needed to enable successfully running optimal tests and collecting accurate results. The data acquisition system and the associated software were updated and customized to adapt to the changes implemented on the test rig system and to accommodate the data produced by various sensor technologies. Discussion and presentation of these updates and the new attributes implemented are herein reported
Author
DATA ACQUISITION; SOFTWARE ENGINEERING; HUMAN-COMPUTER INTERFACE; RESEARCH FACILITIES; TURBINE ENGINES; DATA PROCESSING
Additions to the NASA Aeronautics and Space Database as of 11/08/2011
20110016582 NASA Marshall Space Flight Center, Huntsville, AL, United States
Meteoroids: The Smallest Solar System Bodies
Moser, Danille E., Compiler; Hardin, B. F., Compiler; Janches, Diego, Compiler; July 2011; In English; Meteoroids Conference 2010: An International Conference on Minor Bodies in the Solar System, 24-28 May 2010, Breckenridge, CO, United States; Original contains color illustrations
Report No.(s): NASA/CP-2011-216469; M-1318; Copyright; Distribution as joint owner in the copyright; Availability: CASI
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This volume is a compilation of articles reflecting the current state of knowledge on the physics, chemistry, astronomy, and aeronomy of small bodies in the solar system. The articles included here represent the most recent results in meteor, meteoroid, and related research fields and were presented May 24-28, 2010, in Breckenridge, Colorado, USA at Meteoroids 2010: An International Conference on Minor Bodies in the Solar System.
Author
METEOROIDS; AERONOMY; REFLECTION; BOLIDES; ASTEROIDS; COMETS
20110016583 European Space Agency. European Space Research and Technology Center, ESTEC, Noordwijk, Netherlands
Constraining the Physical Properties of Meteor Stream Particles by Light Curve Shapes Using the Virtual Meteor Observatory
Koschny, D.; Gritsevich, M.; Barentsen, G.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 156-16; In English; Original contains color illustrations
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Different authors have produced models for the physical properties of meteoroids based on the shape of a meteor's light curve, typically from short observing campaigns. We here analyze the height profiles and light curves of approx.200 double-station meteors from the Leonids and Perseids using data from the Virtual Meteor Observatory, to demonstrate that with this web-based meteor database it is possible to analyze very large datasets from different authors in a consistent way. We compute the average heights for begin point, maximum luminosity, and end heights for Perseids and Leonids. We also compute the skew of the light curve, usually called the F-parameter. The results compare well with other author's data. We display the average light curve in a novel way to assess the light curve shape in addition to using the F-parameter. While the Perseids show a peaked light curve, the average Leonid light curve has a more flat peak. This indicates that the particle distribution of Leonid meteors can be described by a Gaussian distribution; the Perseids can be described with a power law. The skew for Leonids is smaller than for Perseids, indicating that the Leonids are more fragile than the Perseids.
Author
LEONID METEOROIDS; NORMAL DENSITY FUNCTIONS; BRIGHTNESS; FLIGHT PATHS; STREAMS; LIGHT CURVE; LUMINOSITY; METEOROIDS
20110016584 Los Alamos National Lab., NM, United States
Analysis of ALTAIR 1998 Meteor Radar Data
Zinn, J.; Close, S.; Colestock, P. L.; MacDonell, A.; Loveland, R.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 268-27; In English
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We describe a new analysis of a set of 32 UHF meteor radar traces recorded with the 422 MHz ALTAIR radar facility in November 1998. Emphasis is on the velocity measurements, and on inferences that can be drawn from them regarding the meteor masses and mass densities. We find that the velocity vs altitude data can be fitted as quadratic functions of the path integrals of the atmospheric densities vs distance, and deceleration rates derived from those fits all show the expected behavior of increasing with decreasing altitude. We also describe a computer model of the coupled processes of collisional heating, radiative cooling, evaporative cooling and ablation, and deceleration - for meteors composed of defined mixtures of mineral constituents. For each of the cases in the data set we ran the model starting with the measured initial velocity and trajectory inclination, and with various trial values of the quantity mPs 2 (the initial mass times the mass density squared), and then compared the computed deceleration vs altitude curves vs the measured ones. In this way we arrived at the best-fit values of the mPs 2 for each of the measured meteor traces. Then further, assuming various trial values of the density Ps, we compared the computed mass vs altitude curves with similar curves for the same set of meteors determined previously from the measured radar cross sections and an electrostatic scattering model. In this way we arrived at estimates of the best-fit mass densities Ps for each of the cases. Keywords meteor ALTAIR radar analysis 1 Introduction This paper describes a new analysis of a set of 422 MHz meteor scatter radar data recorded with the ALTAIR High-Power-Large-Aperture radar facility at Kwajalein Atoll on 18 November 1998. The exceptional accuracy/precision of the ALTAIR tracking data allow us to determine quite accurate meteor trajectories, velocities and deceleration rates. The measurements and velocity/deceleration data analysis are described in Sections II and III. The main point of this paper is to use these deceleration rate data, together with results from a computer model, to determine values of the quantities mPs 2 (the meteor mass times its material density squared); and further, by combining these m s 2 values with meteor mass estimates for the same set of meteors determined separately from measured radar scattering
Author
ATMOSPHERIC DENSITY; RADAR SCATTERING; ULTRAHIGH FREQUENCIES; RADAR DATA; METEOROIDS; RADAR CROSS SECTIONS
20110016585 University of Western Ontario, London, Ontario, Canada
Video Meteor Fluxes
Campbell-Brown, M. D.; Braid, D.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 304-31; In English
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The flux of meteoroids, or number of meteoroids per unit area per unit time, is critical for calibrating models of meteoroid stream formation and for estimating the hazard to spacecraft from shower and sporadic meteors. Although observations of meteors in the millimetre to centimetre size range are common, flux measurements (particularly for sporadic meteors, which make up the majority of meteoroid flux) are less so. It is necessary to know the collecting area and collection time for a given set of observations, and to correct for observing biases and the sensitivity of the system. Previous measurements of sporadic fluxes are summarized in Figure 1; the values are given as a total number of meteoroids striking the earth in one year to a given limiting mass. The Gr n et al. (1985) flux model is included in the figure for reference. Fluxes for sporadic meteoroids impacting the Earth have been calculated for objects in the centimeter size range using Super-Schmidt observations (Hawkins & Upton, 1958); this study used about 300 meteors, and used only the physical area of overlap of the cameras at 90 km to calculate the flux, corrected for angular speed of meteors, since a large angular speed reduces the maximum brightness of the meteor on the film, and radiant elevation, which takes into account the geometric reduction in flux when the meteors are not perpendicular to the horizontal. They bring up corrections for both partial trails (which tends to increase the collecting area) and incomplete overlap at heights other than 90 km (which tends to decrease it) as effects that will affect the flux, but estimated that the two effects cancelled one another. Halliday et al. (1984) calculated the flux of meteorite-dropping fireballs with fragment masses greater than 50 g, over the physical area of sky accessible to the MORP fireball cameras, counting only observations in clear weather. In the micron size range, LDEF measurements of small craters on spacecraft have been used to estimate the flux (Love & Brownlee, 1993); here the physical area of the detector is well known, but the masses depend strongly on the unknown velocity distribution. In the same size range, Thomas & Netherway (1989) used the narrow-beam radar at Jindalee to calculate the flux of sporadics. In between these very large and very small sizes, a number of video and photographic observations were reduced by Ceplecha (2001). These fluxes were calculated (details are given in Ceplecha, 1988) taking the Halliday et al. (1984) MORP fireball fluxes, slightly corrected in mass, as a calibration, and adjusting the flux of small cameras to overlap with the number/mass relation from that work.
Author
METEOROID CONCENTRATION; METEOROIDS; METEORITES; MILLIMETER WAVES; VELOCITY DISTRIBUTION; BRIGHTNESS; SPORADIC METEOROIDS
20110016587 Academy of Sciences of the the Republic of Tajikistan, Tajikistan
The Trajectory, Orbit and Preliminary Fall Data of the JUNE BOOTID Superbolide of July 23, 2008
Konovalova, N. A.; Madiedo, J. M.; Trigo-Rodriguez, J. M.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 251-25; In English; Original contains color illustrations
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The results of the atmospheric trajectory, radiant, orbit and preliminary fall data calculations of an extremely bright slow-moving fireball are presented. The fireball had a -20.7 maximum absolute magnitude and the spectacular long-persistence dust trail (Fig 1 and 2) was observed in a widespread region of Tajikistan twenty eight minutes after sunset, precisely at 14h 45m 25s UT on July 23, 2008. The bolide was first recorded at a height of 38.2 km, and attained its maximum brightness at a height of 35.0 km and finished at a height of 19.6 km. These values are very much in line with other well-known fireballs producing meteorites. The first break-up must have occurred under an aerodynamic pressure Pdyn of about 1.5 MPa, similar to those derived from the study of atmospheric break-ups of previously reported meteorite-dropping bolides. Our trajectory, and dynamic results suggest that one might well expect to find meteorites on the ground in this case. The heliocentric orbit of the meteoroid determined from the observations is very similar to the mean orbit of the June Bootid meteor shower, whose parental comet is 7P/Pons-Winnecke (Lindblad et al. 2003). If the parent was indeed a comet, this has implications for the internal structure of comets, and for the survivability of cometary meteorites.
Author
METEOROID SHOWERS; METEORITES; SHOCK WAVES; STELLAR MAGNITUDE; SOLAR ORBITS; METEOROIDS; DUST; COMETS
20110016588 San Jose State Univ., San Jose, CA, United States
A Numerical Study of Micrometeoroids Entering Titan's Atmosphere
Templeton, M.; Kress, M. E.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 212-21; In English; Original contains color illustrations
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A study using numerical integration techniques has been performed to analyze the temperature profiles of micrometeors entering the atmosphere of Saturn s moon Titan. Due to Titan's low gravity and dense atmosphere, arriving meteoroids experience a significant cushioning effect compared to those entering the Earth's atmosphere. Temperature profiles are presented as a function of time and altitude for a number of different meteoroid sizes and entry velocities, at an entry angle of 45. Titan's micrometeoroids require several minutes to reach peak heating (ranging from 200 to 1200 K), which occurs at an altitude of about 600 km. Gentle heating may allow for gradual evaporation of volatile components over a wide range of altitudes. Computer simulations have been performed using the Cassini/Huygens atmospheric data for Titan. Keywords micrometeoroid Titan atmosphere 1 Introduction On Earth, incoming micrometeoroids (~100 m diameter) are slowed by collisions with air molecules in a relatively compact atmosphere, resulting in extremely rapid deceleration and a short heating pulse, often accompanied by brilliant meteor displays. On Titan, lower gravity leads to an atmospheric scale height that is much larger than on Earth. Thus, deceleration of meteors is less rapid and these particles undergo more gradual heating. This study uses techniques similar to those used for Earth meteoroid studies [1], exchanging Earth s planetary characteristics (e.g., mass and atmospheric profile) for those of Titan. Cassini/Huygens atmospheric data for Titan were obtained from the NASA Planetary Atmospheres Data Node [4]. The objectives of this study were 1) to model atmospheric heating of meteoroids for a range of micrometeor entry velocities for Titan, 2) to determine peak heating temperatures and rates for micrometeoroids entering Titan s atmosphere, and 3) to create a general simulation environment that can be extended to incorporate additional parameters and variables, including different atmospheric, meteoroid and planetary data. The micrometeoroid entry simulations made using Titan atmospheric data assume that, as on Earth, micrometeors are heated by collision with molecules in the atmosphere. Unlike on Earth where heating pulses last a few seconds and reach temperatures sufficient to melt silicates (> 1600 K [1]),
Author
ATMOSPHERIC HEATING; TITAN ATMOSPHERE; DISPLAY DEVICES; EARTH ATMOSPHERE; MEASURE AND INTEGRATION; MICROGRAVITY; METEOROIDS
20110016589 Pennsylvania State Univ., University Park, PA, United States
Global Variation of Meteor Trail Plasma Turbulence
Dyrud, L. P.; Hinrichs, J.; Urbina, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 217-23; In English; Original contains color illustrations
Contract(s)/Grant(s): NSF ATM-0613706; NSF ATM-0638912
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We present the first global simulations on the occurrence of meteor trail plasma irregularities. These results seek to answer the following questions: when a meteoroid disintegrates in the atmosphere will the resulting trail become plasma turbulent, what are the factors influencing the development of turbulence, and how do they vary on a global scale. Understanding meteor trail plasma turbulence is important because turbulent meteor trails are visible as non-specular trails to coherent radars, and turbulence influences the evolution of specular radar meteor trails, particularly regarding the inference of mesospheric temperatures from trail diffusion rates, and their usage for meteor burst communication. We provide evidence of the significant effect that neutral atmospheric winds and density, and ionospheric plasma density have on the variability of meteor trail evolution and the observation of nonspecular meteor trails, and demonstrate that trails are far less likely to become and remain turbulent in daylight, explaining several observational trends using non-specular and specular meteor trails.
Author
METEOR TRAILS; METEOROID SHOWERS; MESOSPHERE; PLASMA DENSITY; MAGNETIC FIELDS; MAGNETOHYDRODYNAMIC STABILITY; ATMOSPHERIC CIRCULATION; RADAR RANGE
20110016590 Instituto Nazionale Di Astrofisica, Rome, Italy
Stream Lifetimes Against Planetary Encounters
Valsecchi, G. B.; Lega, E.; Froeschle, Cl.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 19-2; In English; Original contains color illustrations
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We study, both analytically and numerically, the perturbation induced by an encounter with a planet on a meteoroid stream. Our analytical tool is the extension of pik s theory of close encounters, that we apply to streams described by geocentric variables. The resulting formulae are used to compute the rate at which a stream is dispersed by planetary encounters into the sporadic background. We have verified the accuracy of the analytical model using a numerical test.
Author
METEOROIDS; STREAMS; SOLAR ORBITS; PERTURBATION; METEORITE COLLISIONS; ENCOUNTERS
20110016591 University of Western Ontario, London, Ontario, Canada
Multi-Year CMOR Observations of the Geminid Meteor Shower
Webster, A. R.; Jones, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 48-5; In English
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The three-station Canadian Meteor Orbit Radar (CMOR) is used here to examine the Geminid meteor shower with respect to variation in the stream properties including the flux and orbital elements over the period of activity in each of the consecutive years 2005 2008 and the variability from year to year. Attention is given to the appropriate choice and use of the D-criterion in the separating the shower meteors from the sporadic background.
Author
SOLAR LONGITUDE; ORBITAL ELEMENTS; GEMINID METEOROIDS; METEOROID SHOWERS; METEOROIDS
20110016592 Taras Shevchenko National Univ., Kyiv, Ukraine
Formation of the Aerosol of Space Origin in Earth's Atmosphere
Kozak, P. M.; Kruchynenko, V. G.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 181-19; In English
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The problem of formation of the aerosol of space origin in Earth s atmosphere is examined. Meteoroids of the mass range of 10-18-10-8 g are considered as a source of its origin. The lower bound of the mass range is chosen according to the data presented in literature, the upper bound is determined in accordance with the theory of Whipple s micrometeorites. Basing on the classical equations of deceleration and heating for small meteor bodies we have determined the maximal temperatures of the particles, and altitudes at which they reach critically low velocities, which can be called as velocities of stopping . As a condition for the transformation of a space particle into an aerosol one we have used the condition of non-reaching melting temperature of the meteoroid. The simplified equation of deceleration without earth gravity and barometric formula for the atmosphere density are used. In the equation of heat balance the energy loss for heating is neglected. The analytical solution of the simplified equations is used for the analysis.
Author
AEROSOLS; ATMOSPHERIC DENSITY; ATMOSPHERIC PRESSURE; DENSITY DISTRIBUTION; ENERGY DISSIPATION; MICROMETEORITES; METEOROIDS; GRAVITATION
20110016593 University of Western Ontario, London, Ontario, Canada
Preliminary Results on the Gravitational Slingshot Effect and the Population of Hyperbolic Meteoroids at Earth
Wiegert, P. A.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 106-11; In English
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Interstellar meteoroids, solid particles arriving from outside our Solar System, are not easily distinguished from local meteoroids. A velocity above the escape velocity of the Sun is often used as an indicator of a possible interstellar origin. We demonstrate that the gravitational slingshot effect, resulting from the passage of local meteoroid near a planet, can produce hyperbolic meteoroids at the Earth s orbit with excess velocities comparable to those expected of interstellar meteoroids.
Author
GRAVITATIONAL EFFECTS; METEOROIDS; ULYSSES MISSION; EARTH ORBITS; GALILEO SPACECRAFT; DUST; VELOCITY DISTRIBUTION
20110016594 NASA Marshall Space Flight Center, Huntsville, AL, United States
An Exponential Luminous Efficiency Model for Hypervelocity Impact into Regolith
Swift, W. R.; Moser, D. E.; Suggs, R. M.; Cooke, W. J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 125-14; In English; Original contains color illustrations
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The flash of thermal radiation produced as part of the impact-crater forming process can be used to determine the energy of the impact if the luminous efficiency is known. From this energy the mass and, ultimately, the mass flux of similar impactors can be deduced. The luminous efficiency, eta, is a unique function of velocity with an extremely large variation in the laboratory range of under 6 km/s but a necessarily small variation with velocity in the meteoric range of 20 to 70 km/s. Impacts into granular or powdery regolith, such as that on the moon, differ from impacts into solid materials in that the energy is deposited via a serial impact process which affects the rate of deposition of internal (thermal) energy. An exponential model of the process is developed which differs from the usual polynomial models of crater formation. The model is valid for the early time portion of the process and focuses on the deposition of internal energy into the regolith. The model is successfully compared with experimental luminous efficiency data from both laboratory impacts and from lunar impact observations. Further work is proposed to clarify the effects of mass and density upon the luminous efficiency scaling factors. Keywords hypervelocity impact impact flash luminous efficiency lunar impact meteoroid 1
Author
HYPERVELOCITY IMPACT; LUMINOSITY; REGOLITH; INTERNAL ENERGY; CRATERING; THERMAL ENERGY; THERMAL RADIATION; IMPACTORS
20110016595 NASA Marshall Space Flight Center, Huntsville, AL, United States
Lunar Meteoroid Impact Observations and the Flux of Kilogram-sized Meteoroids
Suggs, R. M.; Cooke, W. J.; Koehler, H. M.; Suggs, R. J.; Moser, D. E.; Swift, W. R.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 116-12; In English; Original contains color illustrations
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Lunar impact monitoring provides useful information about the flux of meteoroids in the hundreds of grams to kilograms size range. The large collecting area of the night side of the lunar disk, approximately 3.8 10(exp 6)sq km in our camera field-of-view, provides statistically significant counts of the meteoroids striking the lunar surface. Over 200 lunar impacts have been observed by our program in roughly 4 years. Photometric calibration of the flashes observed in the first 3 years along with the luminous efficiency determined using meteor showers and hypervelocity impact tests (Bellot Rubio et al. 2000; Ortiz et al. 2006; Moser et al. 2010; Swift et al. 2010) provide their impact kinetic energies. The asymmetry in the flux on the evening and morning hemispheres of the Moon is compared with sporadic and shower sources to determine their most likely origin. These measurements are consistent with other observations of large meteoroid fluxes.
Author
METEORITE COLLISIONS; METEOROID CONCENTRATION; METEOROID SHOWERS; HYPERVELOCITY IMPACT; FIELD OF VIEW; IMPACT TESTS; METEOROIDS
20110016596 Pennsylvania State Univ., University Park, PA, United States
The New Meteor Radar at Penn State: Design and First Observations
Urbina, J.; Seal, R.; Dyrud, L.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 357-36; In English; Original contains color illustrations
Contract(s)/Grant(s): ATM-0638624; ATM-0457156
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In an effort to provide new and improved meteor radar sensing capabilities, Penn State has been developing advanced instruments and technologies for future meteor radars, with primary objectives of making such instruments more capable and more cost effective in order to study the basic properties of the global meteor flux, such as average mass, velocity, and chemical composition. Using low-cost field programmable gate arrays (FPGAs), combined with open source software tools, we describe a design methodology enabling one to develop state-of-the art radar instrumentation, by developing a generalized instrumentation core that can be customized using specialized output stage hardware. Furthermore, using object-oriented programming (OOP) techniques and open-source tools, we illustrate a technique to provide a cost-effective, generalized software framework to uniquely define an instrument s functionality through a customizable interface, implemented by the designer. The new instrument is intended to provide instantaneous profiles of atmospheric parameters and climatology on a daily basis throughout the year. An overview of the instrument design concepts and some of the emerging technologies developed for this meteor radar are presented.
Author
ATMOSPHERIC ENTRY; METEOROID CONCENTRATION; METEOROIDS; FIELD-PROGRAMMABLE GATE ARRAYS; CHEMICAL COMPOSITION; EARTH ATMOSPHERE; GRAVITY WAVES; IMAGING TECHNIQUES
20110016597 NASA Marshall Space Flight Center, Huntsville, AL, United States
Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids
Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; Koehler, H. M.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 142-15; In English; Original contains color illustrations
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Since early 2006, NASA s Marshall Space Flight Center has been routinely monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 12 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. (2000a, b) for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-800 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated from the observed flash intensity.
Author
HYPERVELOCITY IMPACT; METEORITE COLLISIONS; METEOROID SHOWERS; TAURID METEOROIDS; LUMINOSITY; GEMINID METEOROIDS
20110016598 Academy of Sciences of the the Republic of Tajikistan, Tajikistan
Large Bodies Associated with Meteoroid Streams
Badadzhanov, P. B.; William, I. P.; Kokhirova, G. I.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 14-1; In English
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It is now accepted that some near-Earth objects (NEOs) may be dormant or dead comets. One strong indicator of cometary nature is the existence of an associated meteoroid stream with its consequently observed meteor showers. The complexes of NEOs which have very similar orbits and a likely common progenitor have been identified. The theoretical parameters for any meteor shower that may be associated with these complexes were calculated. As a result of a search of existing catalogues of meteor showers, activity has been observed corresponding to each of the theoretically predicted showers was found. We conclude that these asteroid-meteoroid complexes of four NEOs moving within the Piscids stream, three NEOs moving within the Iota Aquariids stream, and six new NEOs added to the Taurid complex are the result of a cometary break-up.
Author
TAURID METEOROIDS; METEOROID SHOWERS; NEAR EARTH OBJECTS; STREAMS; ASTEROIDS; COMETS; METEOROIDS
20110016599 NASA Ames Research Center, Moffett Field, CA, United States
Atmospheric Chemistry of Micrometeoritic Organic Compounds
Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 176-18; In English; Original contains color illustrations
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Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.
Author
ATMOSPHERIC CHEMISTRY; METEOROIDS; MICROMETEORITES; ORGANIC COMPOUNDS; CARBONACEOUS CHONDRITES; COMPLEX COMPOUNDS; EXTRATERRESTRIAL MATTER; HYDROCARBONS; CARBON DIOXIDE; POLYCYCLIC AROMATIC HYDROCARBONS
20110016600 Kharkiv National Univ. of Radioelectronics, Kharkiv, Ukraine
Distributions of Orbital Elements for Meteoroids on Near-Parabolic Orbits According to Radar Observational Data
Kolomiyets, S. V.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 88-10; In English; Original contains color illustrations
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Some results of the International Heliophysical Year (IHY) Coordinated Investigation Program (CIP) number 65 Meteors in the Earth Atmosphere and Meteoroids in the Solar System are presented. The problem of hyperbolic and near-parabolic orbits is discussed. Some possibilities for the solution of this problem can be obtained from the radar observation of faint meteors. The limiting magnitude of the Kharkov, Ukraine, radar observation program in the 1970 s was +12, resulting in a very large number of meteors being detected. 250,000 orbits down to even fainter limiting magnitude were determined in the 1972-78 period in Kharkov (out of them 7,000 are hyperbolic). The hypothesis of hyperbolic meteors was confirmed. In some radar meteor observations 1 10% of meteors are hyperbolic meteors. Though the Advanced Meteor Orbit Radar (AMOR, New Zealand) and Canadian Meteor Orbit Radar (CMOR, Canada) have accumulated millions of meteor orbits, there are difficulties in comparing the radar observational data obtained from these three sites (New Zealand, Canada, Kharkov). A new global program International Space Weather Initiative (ISWI) has begun in 2010 (http://www.iswi-secretariat.org). Today it is necessary to create the unified radar catalogue of nearparabolic and hyperbolic meteor orbits in the framework of the ISWI, or any other different way, in collaboration of Ukraine, Canada, New Zealand, the USA and, possibly, Japan. Involvement of the Virtual Meteor Observatory (Netherlands) and Meteor Data Centre (Slovakia) is desirable too. International unified radar catalogue of near-parabolic and hyperbolic meteor orbits will aid to a major advance in our understanding of the ecology of meteoroids within the Solar System and beyond.
Author
ORBITAL ELEMENTS; METEOROIDS; RADAR DATA; EARTH ATMOSPHERE; ACCUMULATIONS; CATALOGS (PUBLICATIONS); ECOLOGY
20110016601 Academy of Sciences of the Azerbaijan SSR, Azerbaijan
Origin of Short-Perihelion Comets
Guliyev, A. S.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 76-8; In English
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New regularities for short-perihelion comets are found. Distant nodes of cometary orbits of Kreutz family are concentrated in a plane with ascending node 76 and inclination 267 at the distance from 2 up to 3 a.u. and in a very narrow interval of longitudes. There is a correlation dependence between q and cos I concerning the found plane (coefficient of correlation 0.41). Similar results are received regarding to cometary families of Meyer, Kracht and Marsden. Distant nodes of these comets are concentrated close three planes (their parameters are discussed in the article) and at distances 1.4; 0.5; 6 a.u. accordingly. It is concluded that these comet groups were formed as a result of collision of parent bodies with meteoric streams. One more group, consisting of 7 comets is identified. 5 comet pairs are selected among sungrazers.
Author
COMETS; STELLAR EVOLUTION; STREAMS; METEOROIDS; PERIHELIONS; CORRELATION COEFFICIENTS
20110016602 Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Berlin, Germany
Composition of LHB Comets and Their Influence on the Early Earth Atmosphere Composition
Tornow, C.; Kupper, S.; Ilgner, M.; Kuehrt, E.; Motschmann, U.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 192-20; In English; Original contains color illustrations
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Two main processes were responsible for the composition of this atmosphere: chemical evolution of the volatile fraction of the accretion material forming the planet and the delivery of gasses to the planetary surface by impactors during the late heavy bombardment (LHB). The amount and composition of the volatile fraction influences the outgassing of the Earth mantle during the last planetary formation period. A very weakened form of outgassing activity can still be observed today by examining the composition of volcanic gasses. An enlightenment of the second process is based on the sparse records of the LHB impactors resulting from the composition of meteorites, observed cometary comas, and the impact material found on the Moon. However, for an assessment of the influence of the outgassing on the one hand and the LHB event on the other, one has to supplement the observations with numerical simulations of the formation of volatiles and their incorporation into the accretion material which is the precursors of planetary matter, comets and asteroids. These simulations are performed with a combined hydrodynamic-chemical model of the solar nebula (SN). We calculate the chemical composition of the gas and dust phase of the SN. From these data, we draw conclusions on the upper limits of the water content and the amount of carbon and nitrogen rich volatiles incorporated later into the accretion material. Knowing these limits we determine the portion of major gas compounds delivered during the LHB and compare it with the related quantities of the outgassed species.
Author
COMETARY COLLISIONS; CHEMICAL COMPOSITION; ASTRONOMICAL MODELS; ASTEROIDS; COMETS; GAS COMPOSITION; MOISTURE CONTENT; PLANETARY EVOLUTION; METEORITIC COMPOSITION; CHEMICAL EVOLUTION
20110016603 Utrecht Univ., Utrecht, Netherlands
Maximizing the Performance of Automated Low Cost All-sky Cameras
Bettonvil, F.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 363-36; In English; Original contains black and white illustrations
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Thanks to the wide spread of digital camera technology in the consumer market, a steady increase in the number of active All-sky camera has be noticed European wide. In this paper I look into the details of such All-sky systems and try to optimize the performance in terms of accuracy of the astrometry, the velocity determination and photometry. Having autonomous operation in mind, suggestions are done for the optimal low cost All-sky camera.
Author
DIGITAL CAMERAS; IMAGING TECHNIQUES; METEORITES; METEOROIDS; ASTROMETRY; PHOTOMETRY; DIGITAL SYSTEMS
20110016604 Slovak Academy of Sciences, Bratislava, Slovakia
The Distribution of the Orbits in the Geminid Meteoroid Stream Based on the Dispersion of their Periods
Hajdukova, M., Jr.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 58-6; In English
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Geminid meteoroids, selected from a large set of precisely-reduced meteor orbits from the photographic and radar catalogues of the IAU Meteor Data Center (Lindblad et al. 2003), and from the Japanese TV meteor shower catalogue (SonotaCo 2010), have been analyzed with the aim of determining the orbits distribution in the stream, based on the dispersion of their periods P . The values of the reciprocal semi-major axis 1/a in the stream showed small errors in the velocity measurements. Thus, it was statistically possible to also determine the relation between the observed and the real dispersion of the Geminids.
Author
METEOROID SHOWERS; ORBITAL ELEMENTS; ASTRONOMY; EARTH ORBITS; GEMINID METEOROIDS; PLANETARY RADIATION; METEOROIDS; GRAVITATIONAL EFFECTS
20110016605 London Univ., United Kingdom
Dynamical Evolution of Meteoroid Streams, Developments Over the Last 30 Years
Williams, I. P.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 2-; In English
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As soon as reliable methods for observationally determining the heliocentric orbits of meteoroids and hence the mean orbit of a meteoroid stream in the 1950s and 60s, astronomers strived to investigate the evolution of the orbit under the effects of gravitational perturbations from the planets. At first, the limitations in the capabilities of computers, both in terms of speed and memory, placed severe restrictions on what was possible to do. As a consequence, secular perturbation methods, where the perturbations are averaged over one orbit became the norm. The most popular of these is the Halphen- Goryachev method which was used extensively until the early 1980s. The main disadvantage of these methods lies in the fact that close encounter can be missed, however they remain useful for performing very long-term integrations. Direct integration methods determine the effects of the perturbing forces at many points on an orbit. This give a better picture of the orbital evolution of an individual meteoroid, but many meteoroids have to be integrated in order to obtain a realistic picture of the evolution of a meteoroid stream. The notion of generating a family of hypothetical meteoroids to represent a stream and directly integrate the motion of each was probably first used by Williams Murray & Hughes (1979), to investigate the Quadrantids. Because of computing limitations, only 10 test meteoroids were used. Only two years later, Hughes et. al. (1981) had increased the number of particles 20-fold to 200 while after a further year, Fox Williams and Hughes used 500 000 test meteoroids to model the Geminid stream. With such a number of meteoroids it was possible for the first time to produce a realistic cross-section of the stream on the ecliptic. From that point on there has been a continued increase in the number of meteoroids, the length of time over which integration is carried out and the frequency with which results can be plotted so that it is now possible to produce moving images of the stream. As a consequence, over recent years, emphasis has moved to considering stream formation and the role fragmentation plays in this.
Author
METEOROIDS; STREAMS; SOLAR ORBITS; GEMINID METEOROIDS; MEASURE AND INTEGRATION; NUMERICAL INTEGRATION; ORBIT PERTURBATION
20110016606 National Astronomical Observatory, Tokyo, Japan
Meteor Shower Activity Derived from "Meteor Watching Public-Campaign" in Japan
Sato, M.; Watanabe, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 31-3; In English
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We tried to analyze activities of meteor showers from accumulated data collected by public campaigns for meteor showers which were performed as outreach programs. The analyzed campaigns are Geminids (in 2007 and 2009), Perseids (in 2008 and 2009), Quadrantids (in 2009) and Orionids (in 2009). Thanks to the huge number of reports, the derived time variations of the activities of meteor showers is very similar to those obtained by skilled visual observers. The values of hourly rates are about one-fifth (Geminids 2007) or about one-fourth (Perseids 2008) compared with the data of skilled observers, mainly due to poor observational sites such as large cities and urban areas, together with the immature skill of participants in the campaign. It was shown to be highly possible to estimate time variation in the meteor shower activity from our campaign.
Author
METEOROID SHOWERS; ASTRONOMY; EXTRACTION; ASTRONOMICAL OBSERVATORIES; ACCUMULATIONS
20110016607 Institut de Mecanique Celeste, Paris, France
French Meteor Network for High Precision Orbits of Meteoroids
Atreya, P.; Vaubaillon, J.; Colas, F.; Bouley, S.; Gaillard, B.; Sauli, I.; Kwon, M. K.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 344-35; In English; Original contains color illustrations
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There is a lack of precise meteoroids orbit from video observations as most of the meteor stations use off-the-shelf CCD cameras. Few meteoroids orbit with precise semi-major axis are available using film photographic method. Precise orbits are necessary to compute the dust flux in the Earth s vicinity, and to estimate the ejection time of the meteoroids accurately by comparing them with the theoretical evolution model. We investigate the use of large CCD sensors to observe multi-station meteors and to compute precise orbit of these meteoroids. An ideal spatial and temporal resolution to get an accuracy to those similar of photographic plates are discussed. Various problems faced due to the use of large CCD, such as increasing the spatial and the temporal resolution at the same time and computational problems in finding the meteor position are illustrated.
Author
CCD CAMERAS; DRACONID METEOROIDS; METEOROIDS; ORBITAL ELEMENTS; HIGH RESOLUTION; ASTROMETRY; CHARGE COUPLED DEVICES; SPATIAL RESOLUTION; TEMPORAL RESOLUTION
20110016608 University of Western Ontario, London, Ontario, Canada
An Investigation of How a Meteor Light Curve is Modified by Meteor Shape and Atmospheric Density Perturbations
Stokan, E.; Campbell-Brown, M. D.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 163-16; In Afrikaans
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This is a preliminary investigation of how perturbations to meteoroid shape or atmospheric density affect a meteor light curve. A simple equation of motion and ablation are simultaneously solved numerically to give emitted light intensity as a function of height. It is found that changing the meteoroid shape, by changing the relationship between the cross-section area and the mass, changes the curvature and symmetry of the light curve, while making a periodic oscillation in atmospheric density gives a small periodic oscillation in the light curve.
Author
ABLATION; METEOROID CONCENTRATION; PERTURBATION; SAMPLE RETURN MISSIONS; PLANETARY EVOLUTION; LUMINOUS INTENSITY; ATMOSPHERIC DENSITY; LIGHT CURVE
20110016609 Academy of Sciences of the the Republic of Tajikistan, Tajikistan
Dependences of Ratio of the Luminosity to Ionization on Velocity and Chemical Composition of Meteors
Narziev, M.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 168-17; In English; Original contains color illustrations
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On the bases of results simultaneous photographic and radio echo observations, the results complex radar and television observations of meteors and also results of laboratory modeling of processes of a luminescence and ionization, correlation between of luminous intensity Ip to linear electronic density q from of velocities and chemical structure are investigated. It is received that by increasing value of velocities of meteors and decrease of nuclear weight of substance of particles, lg Ip/q decreased more than one order.
Author
LUMINOUS INTENSITY; METEORITIC COMPOSITION; METEOROIDS; RADAR TRACKING; RADIO ECHOES; CHEMICAL COMPOSITION; IONIZATION; LUMINOSITY
20110016610 Nippon Meteor Society, Hachioji, Japan
Identification of Optical Component of North Toroidal Source of Sporadic Meteors and its Origin
Hashimoto, T.; Watanabe, J.; Sato, M.; Ishiguro, M.; et al.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 82-8; In English; Original contains color illustrations
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We succeeded to identify the North Toroidal source by optical observations performed by the SonotaCo Network, which is a TV observation network coordinated by Japanese amateurs. This source has been known only for radar observations until now. The orbits of the optical meteors in the North Toroidal source are relatively large eccentricity and semi-major axis, compared with those of the radar meteors. In this paper, we report the characteristics of this North Toroidal source detected by optical observations, and discuss the possible origin and evolution of this source.
Author
RADAR TRACKING; HIGH RESOLUTION; METEOROIDS; OPTICAL EQUIPMENT; VISUAL OBSERVATION; RADAR RESOLUTION
20110016611 University of Western Ontario, London, Ontario, Canada
Infrasonic Detection of a Large Bolide over South Sulawesi, Indonesia on October 8, 2009: Preliminary Results
Silber, E. A.; Brown, P. G.; Le Pinchon, A.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 255-26; In English; Original contains color illustrations
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In the morning hours of October 8, 2009, a bright object entered Earth's atmosphere over South Sulawesi, Indonesia. This bolide disintegrated above the ground, generating stratospheric infrasound returns that were detected by infrasonic stations of the global International Monitoring System (IMS) Network of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) at distances up to 17 500 km. Here we present instrumental recordings and preliminary results of this extraordinary event. Using the infrasonic period-yield relations, originally derived for atmospheric nuclear detonations, we find the most probable source energy for this bolide to be 70+/-20 kt TNT equivalent explosive yield. A unique aspect of this event is the fact that it was apparently detected by infrasound only. Global events of such magnitude are expected only once per decade and can be utilized to calibrate infrasonic location and propagation tools on a global scale, and to evaluate energy yield formula, and event timing.
Author
BOLIDES; INFRASONIC FREQUENCIES; AERIAL EXPLOSIONS; IMPACTORS; NEAR EARTH OBJECTS; STRATOSPHERE; DETONATION; EARTH ATMOSPHERE
20110016612 Paris VI Univ., France
Inferring Sources in the Interplanetary Dust Cloud, from Observations and Simulations of Zodiacal Light and Thermal Emission
Levasseur-Regourd, A. C.; Lasue, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 66-7; In English; Original contains color illustrations
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Interplanetary dust particles physical properties may be approached through observations of the solar light they scatter, specially its polarization, and of their thermal emission. Results, at least near the ecliptic plane, on polarization phase curves and on the heliocentric dependence of the local spatial density, albedo, polarization and temperature are summarized. As far as interpretations through simulations are concerned, a very good fit of the polarization phase curve near 1.5 AU is obtained for a mixture of silicates and more absorbing organics material, with a significant amount of fluffy aggregates. In the 1.5-0.5 AU solar distance range, the temperature variation suggests the presence of a large amount of absorbing organic compounds, while the decrease of the polarization with decreasing solar distance is indeed compatible with a decrease of the organics towards the Sun. Such results are in favor of the predominance of dust of cometary origin in the interplanetary dust cloud, at least below 1.5 AU. The implication of these results on the delivery of complex organic molecules on Earth during the LHB epoch, when the spatial density of the interplanetary dust cloud was orders of magnitude greater than today, is discussed.
Author
INTERPLANETARY DUST; LIGHT SCATTERING; THERMODYNAMIC PROPERTIES; ASTEROIDS; ATMOSPHERIC ENTRY; METEOROIDS; LINEAR POLARIZATION; THERMAL EMISSION
20110016613 Academy of Sciences (Russia), Moscow, Russian Federation
Passage of Bolides Through the Atmosphere
Popova, O.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 232-24; In English
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Different fragmentation models are applied to a number of events, including the entry of TC3 2008 asteroid in order to reproduce existing observational data. Keywords meteoroid entry fragmentation modeling 1 Introduction Fragmentation is a very important phenomenon which occurs during the meteoroid entry into the atmosphere and adds more drastic effects than mere deceleration and ablation. Modeling of bolide fragmentation (100 106 kg in mass) may be divided into several approaches. Detail fitting of observational data (deceleration and/or light curves) allows the determination of some meteoroid parameters (ablation and shape-density coefficients, fragmentation points, amount of mass loss) (Ceplecha et al. 1993; Ceplecha and ReVelle 2005). Observational data with high accuracy are needed for the gross-fragmentation model (Ceplecha et al. 1993), which is used for the analysis of European and Desert bolide networks data. Hydrodynamical models, which describe the entry of the meteoroid including evolution of its material, are applied mainly for large bodies (>106 kg) (Boslough et al. 1994; Svetsov et al. 1995; Shuvalov and Artemieva 2002, and others). Numerous papers were devoted to the application of standard equations for large meteoroid entry in the attempts to reproduce dynamics and/or radiation for different bolides and to predict meteorite falls. These modeling efforts are often supplemented by different fragmentation models (Baldwin and Sheaffer, 1971; Borovi.ka et al. 1998; Artemieva and Shuvalov, 2001; Bland and Artemieva, 2006, and others). The fragmentation may occur in different ways. For example, few large fragments are formed. These pieces initially interact through their shock waves and then continue their flight independently. The progressive fragmentation model suggests that meteoroids are disrupted into fragments, which continue their flight as independent bodies and may be disrupted further. Similar models were suggested in numerous papers, beginning with Levin (1956) and initial interaction of fragments started to be taken into account after the paper by Passey and Melosh (1980). The progressive fragmentation model with lateral spreading of formed fragments is widely used (Artemieva and Shuvalov, 1996; Nemtchinov and Popova, 1997; Borovi.ka et al. 1998; Bland and Artemieva, 2006).
Author
METEOROIDS; FRAGMENTATION; SHOCK WAVES; METEORITES; ASTEROIDS; ABLATION
20110016614 Oregon Univ., Eugene, OR, United States
Constraining the Drag Coefficients of Meteors in Dark Flight
Carter, R. T.; Jandir, P. S.; Kress, M. E.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 243-25; In English; Original contains black and white illustrations
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Based on data in the aeronautics literature, we have derived functions for the drag coefficients of spheres and cubes as a function of Mach number. Experiments have shown that spheres and cubes exhibit an abrupt factor-of-two decrease in the drag coefficient as the object slows through the transonic regime. Irregularly shaped objects such as meteorites likely exhibit a similar trend. These functions are implemented in an otherwise simple projectile motion model, which is applicable to the non-ablative dark flight of meteors (speeds less than .+3 km/s). We demonstrate how these functions may be used as upper and lower limits on the drag coefficient of meteors whose shape is unknown. A Mach-dependent drag coefficient is potentially important in other planetary and astrophysical situations, for instance, in the core accretion scenario for giant planet formation.
Author
AERODYNAMIC COEFFICIENTS; METEORITES; SPHERES; CUBES (MATHEMATICS); MACH NUMBER; METEOROIDS; PLANETARY EVOLUTION; AERODYNAMIC DRAG
20110016615 Adam Mickiewicz Univ., Poznan, Poland
The Working Group on Meteor Showers Nomenclature: a History, Current Status and a Call for Contributions
Jopek, T. J.; Jenniskens, P. M.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 7-1; In English
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During the IAU General Assembly in Rio de Janeiro in 2009, the members of Commission 22 established the Working Group on Meteor Shower Nomenclature, from what was formerly the Task Group on Meteor Shower Nomenclature. The Task Group had completed its mission to propose a first list of established meteor showers that could receive officially names. At the business meeting of Commission 22 the list of 64 established showers was approved and consequently officially accepted by the IAU. A two-step process is adopted for showers to receive an official name from the IAU: i) before publication, all new showers discussed in the literature are first added to the Working List of Meteor Showers, thereby receiving a unique name, IAU number and three-letter code; ii) all showers which come up to the verification criterion are selected for inclusion in the List of Established Meteor Showers, before being officially named at the next IAU General Assembly.
Author
METEOROID SHOWERS; METEOROIDS; COMMERCE
20110016616 San Jose State Univ., San Jose, CA, United States
Modeling the Entry of Micrometeoroids into the Atmospheres of Earth-like Planets
Pevyhouse, A. R.; Kress, M. E.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 205-21; In English
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The temperature profiles of micrometeors entering the atmospheres of Earth-like planets are calculated to determine the altitude at which exogenous organic compounds may be released. Previous experiments have shown that flash-heated micrometeorite analogs release organic compounds at temperatures from roughly 500 to 1000 K [1]. The altitude of release is of great importance because it determines the fate of the compound. Organic compounds that are released deeper in the atmosphere are more likely to rapidly mix to lower altitudes where they can accumulate to higher abundances or form more complex molecules and/or aerosols. Variables that are explored here are particle size, entry angle, atmospheric density profiles, spectral type of the parent star, and planet mass. The problem reduces to these questions: (1) How much atmosphere does the particle pass through by the time it is heated to 500 K? (2) Is the atmosphere above sufficient to attenuate stellar UV such that the mixing timescale is shorter than the photochemical timescale for a particular compound? We present preliminary results that the effect of the planetary and particle parameters have on the altitude of organic release.
Author
ATMOSPHERIC ENTRY; ORGANIC COMPOUNDS; ATMOSPHERIC DENSITY; MICROMETEORITES; MICROMETEOROIDS; ORGANIC CHEMISTRY; TEMPERATURE PROFILES; PLANETARY ATMOSPHERES; PHOTOCHEMICAL REACTIONS; AEROSOLS
20110016617 Slovak Academy of Sciences, Tatranska Lomnica, Slovakia
The Updated IAU MDC Catalogue of Photographic Meteor Orbits
Porubcan, V.; Svoren, J.; Neslusan, L.; Schunova, E.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 338-34; In English
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The database of photographic meteor orbits of the IAU Meteor Data Center at the Astronomical Institute SAS has gradually been updated. To the 2003 version of 4581 photographic orbits compiled from 17 different stations and obtained in the period 1936-1996, additional new 211 orbits compiled from 7 sources have been added. Thus, the updated version of the catalogue contains 4792 photographic orbits (equinox J2000.0) available either in two separate orbital and geophysical data files or a file with the merged data. All the updated files with relevant documentation are available at the web of the IAU Meteor Data Center. Keywords astronomical databases photographic meteor orbits 1 Introduction Meteoroid orbits are a basic tool for investigation of distribution and spatial structure of the meteoroid population in the close surroundings of the Earth s orbit. However, information about them is usually widely scattered in literature and often in publications with limited circulation. Therefore, the IAU Comm. 22 during the 1976 IAU General Assembly proposed to establish a meteor data center for collection of meteor orbits recorded by photographic and radio techniques. The decision was confirmed by the next IAU GA in 1982 and the data center was established (Lindblad, 1987). The purpose of the data center was to acquire, format, check and disseminate information on precise meteoroid orbits obtained by multi-station techniques and the database gradually extended as documented in previous reports on the activity of the Meteor Data Center by Lindblad (1987, 1995, 1999 and 2001) or Lindblad and Steel (1993). Up to present, the database consists of 4581 photographic meteor orbits (Lindblad et al., 2005), 63.330 radar determined orbit: Harvard Meteor Project (1961-1965, 1968-1969), Adelaide (1960-1961, 1968-1969), Kharkov (1975), Obninsk (1967-1968), Mogadish (1969-1970) and 1425 video-recordings (Lindblad, 1999) to which additional 817 video meteors orbits published by Koten el al. (2003) were
Author
CATALOGS (PUBLICATIONS); METEOROID CONCENTRATION; METEOROIDS; EARTH ORBITS; DATA ACQUISITION
20110016618 Pennsylvania State Univ., University Park, PA, United States
A Study on Various Meteoroid Disintegration Mechanisms as Observed from the Resolute Bay Incoherent Scatter Radar (RISR)
Malhotra, A.; Mathews, J. D.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 297-30; In English; Original contains color illustrations
Contract(s)/Grant(s): NSF ATM 07-21613; NSF ITR/AP 04-27029
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There has been much interest in the meteor physics community recently regarding the form that meteoroid mass flux arrives in the upper atmosphere. Of particular interest are the relative roles of simple ablation, differential ablation, and fragmentation in the meteoroid mass flux observed by the Incoherent Scatter Radars (ISR). We present here the first-ever statistical study showing the relative contribution of the above-mentioned three mechanisms. These are also one of the first meteor results from the newly-operational Resolute Bay ISR. These initial results emphasize that meteoroid disintegration into the upper atmosphere is a complex process in which all the three above-mentioned mechanisms play an important role though fragmentation seems to be the dominant mechanism. These results prove vital in studying how meteoroid mass is deposited in the upper atmosphere which has important implications to the aeronomy of the region and will also contribute in improving current meteoroid disintegration/ablation models.
Author
AERONOMY; EARTH ATMOSPHERE; EVAPORATION; INCOHERENT SCATTER RADAR; METAL IONS; METEOROID CONCENTRATION; METEOROIDS
20110016619 Pennsylvania State Univ., University Park, PA, United States
Meteoroid Fragmentation as Revealed in Head- and Trail-Echoes Observed with the Arecibo UHF and VHF Radars
Mathews, J. D.; Malhorta, A.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 288-29; In English; Original contains color illustrations
Contract(s)/Grant(s): NSF ATM 07-21613
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We report recent 46.8/430 MHz (VHF/UHF) radar meteor observations at Arecibo Observatory (AO) that reveal many previously unreported features in the radar meteor return - including flare-trails at both UHF and VHF - that are consistent with meteoroid fragmentation. Signature features of fragmentation include strong intra-pulse and pulse-to-pulse fading as the result of interference between or among multiple meteor head-echo returns and between head-echo and impulsive flare or "point" trail-echoes. That strong interference fading occurs implies that these scatterers exhibit well defined phase centers and are thus small compared with the wavelength. These results are consistent with and offer advances beyond a long history of optical and radar meteoroid fragmentation studies. Further, at AO, fragmenting and flare events are found to be a large fraction of the total events even though these meteoroids are likely the smallest observed by the major radars. Fragmentation is found to be a major though not dominate component of the meteors observed at other HPLA radars that are sensitive to larger meteoroids.
Author
METEOROIDS; OPTICAL RADAR; HOLOGRAPHY; ULTRAHIGH FREQUENCIES; TIME MEASUREMENT; RADAR TRACKING; METEOR TRAILS
20110016620 Academy of Sciences of the the Republic of Tajikistan, Tajikistan
Observations of Leonids 2009 by the Tajikistan Fireball Network
Borovicka, J.; Borovicka, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 36-4; In English
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The fireball network in Tajikistan has operated since 2009. Five stations of the network covering the territory of near eleven thousands square kilometers are equipped with all-sky cameras with the Zeiss Distagon "fish-eye" objectives and by digital SLR cameras Nikon with the Nikkor "fish-eye" objectives. Observations of the Leonid activity in 2009 were carried out during November 13-21. In this period, 16 Leonid fireballs have been photographed. As a result of astrometric and photometric reductions, the precise data including atmospheric trajectories, velocities, orbits, light curves, photometric masses and densities were determined for 10 fireballs. The radiant positions during the maximum night suggest that the majority of the fireball activity was caused by the annual stream component with only minor contribution from the 1466 trail. According to the PE criterion, the majority of Leonid fireballs belonged to the most fragile and weak fireball group IIIB. However, one detected Leonid belonged to the fireball group I. This is the first detection of an anomalously strong Leonid individual.
Author
LIGHT CURVE; ORBITAL ELEMENTS; PHOTOMETRY; ASTROMETRY; DIGITAL CAMERAS
20110016621 Universidad de Huelva, Huelva, Spain
Data Reduction and Control Software for Meteor Observing Stations Based on CCD Video Systems
Madiedo, J. M.; Trigo-Rodriguez, J. M.; Lyytinen, E.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 330-33; In English; Original contains black and white illustrations
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The SPanish Meteor Network (SPMN) is performing a continuous monitoring of meteor activity over Spain and neighbouring countries. The huge amount of data obtained by the 25 video observing stations that this network is currently operating made it necessary to develop new software packages to accomplish some tasks, such as data reduction and remote operation of autonomous systems based on high-sensitivity CCD video devices. The main characteristics of this software are described here.
Author
METEOROID SHOWERS; APPLICATIONS PROGRAMS (COMPUTERS); CHARGE COUPLED DEVICES; DATA REDUCTION; METEORITES; METEOROIDS
20110016622 Institut d'Aeronomie Spatiale de Belgique, Brussels, Belgium
BRAMS: The Belgian RAdio Meteor Stations
Lamy, H.; Ranvier, S.; De Keyser, J.; Calders, S.; Gamby, E.; Verbeeck, C.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 351-35; In English
Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016622
In the last months, the Belgian Institute for Space Aeronomy has been developing a Belgian network for observing radio meteors using forward scattering technique. This network is called BRAMS for Belgian RAdio Meteor Stations. Two beacons emitting a circularly polarized pure sine wave toward the zenith act as the transmitters at frequencies of 49.97 and 49.99 MHz. The first one located in Dourbes (Southern Belgium) emits a constant power of 150 Watts while the one located in Ieper (Western Belgium) emits a constant power of 50 Watts. The receiving network consists of about 20 stations hosted mainly by radio amateurs. Two stations have crossed-Yagi antennas measuring horizontal and vertical polarizations of the waves reflected off meteor trails. This will enable a detailed analysis of the meteor power profiles from which physical parameters of the meteoroids can be obtained. An interferometer consisting of 5 Yagi-antennas will be installed at the site of Humain in order to determine the angular detection of one reflection point, allowing us to determine meteoroid trajectories. We describe this new meteor observing facility and present the goals we expect to achieve with the network.
Author
AERONOMY; FORWARD SCATTERING; YAGI ANTENNAS; METEOR TRAILS; METEOROIDS; RADIO METEORS; INTERFEROMETERS
20110016623 NASA Marshall Space Flight Center, Huntsville, AL, United States; Armagh Observatory, Ireland
Numerical Modeling of Cometary Meteoroid Streams Encountering Mars and Venus
Christou, A. A.; Vaubaillon, J.; Meteoroids: The Smallest Solar System Bodies; July 2011; pp. 26-3; In English; Original contains color illustrations
Contract(s)/Grant(s): PP/E002242/1
Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016623
We have simulated numerically the existence of meteoroid streams that encounter the orbits of Mars and Venus, potentially producing meteor showers at those planets. We find that 17 known comets can produce such showers, the intensity of which can be determined through observations. Six of these streams contain dense dust trails capable of producing meteor outbursts.
Author
METEOROID SHOWERS; MARS (PLANET); VENUS (PLANET); STREAMS; DUST; COMETS
Additions to the NASA Aeronautics and Space Database as of 11/11/2011
20110016867 NASA Johnson Space Center, Houston, TX, United States
First Crewed Flight: Rationale, Considerations and Challenges from the Constellation Experience
Noriega, Carlos; Arceneaux, William; Williams, Jeffrey A.; Rhatigan, Jennifer L.; October 2011; In English; Original contains color illustrations
Report No.(s): JSC-CN-24750; NASA/TM-2011-216161; S-1108; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110016867
NASA's Constellation Program has made the most progress in a generation towards building an integrated human-rated spacecraft and launch vehicle. During that development, it became clear that NASA's human-rating requirements lacked the specificity necessary to defend a program plan, particularly human-rating test flight plans, from severe budget challenges. This paper addresses the progress Constellation achieved, problems encountered in clarifying and defending a human-rating certification plan, and discusses key considerations for those who find themselves in similar straits with future human-rated spacecraft and vehicles. We assert, and support with space flight data, that NASA's current human-rating requirements do not adequately address "unknown-unknowns", or the unexpected things the hardware can reveal to the designer during test.
Author
CERTIFICATION; CONSTELLATION PROGRAM; LAUNCH VEHICLES; MANNED SPACECRAFT; AEROSPACE SAFETY; FLIGHT SAFETY; REQUIREMENTS; SPACECRAFT DESIGN
Additions to the NASA Aeronautics and Space Database as of 11/15/2011
20110020259 NASA Glenn Research Center, Cleveland, OH, United States
Materials and Structures Research for Gas Turbine Applications Within the NASA Subsonic Fixed Wing Project
Hurst, Janet; September 2011; In English; Turbo Expo 2010, 14-18 Jun. 2010, Glasgow, Scotland, United Kingdom; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.06.15.10
Report No.(s): NASA/TM-2011-216747; GT2010-23177; E-17324; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020259
A brief overview is presented of the current materials and structures research geared toward propulsion applications for NASA s Subsonic Fixed Wing Project one of four projects within the Fundamental Aeronautics Program of the NASA Aeronautics Research Mission Directorate. The Subsonic Fixed Wing (SFW) Project has selected challenging goals which anticipate an increasing emphasis on aviation s impact upon the global issue of environmental responsibility. These goals are greatly reduced noise, reduced emissions and reduced fuel consumption and address 25 to 30 years of technology development. Successful implementation of these demanding goals will require development of new materials and structural approaches within gas turbine propulsion technology. The Materials and Structures discipline, within the SFW project, comprise cross-cutting technologies ranging from basic investigations to component validation in laboratory environments. Material advances are teamed with innovative designs in a multidisciplinary approach with the resulting technology advances directed to promote the goals of reduced noise and emissions along with improved performance.
Author
FIXED WINGS; GAS TURBINE ENGINES; HIGH TEMPERATURE; OPERATING TEMPERATURE; TURBINE WHEELS; HEAT RESISTANT ALLOYS; ENGINE DESIGN; GAS TURBINES
20110020260 NASA Glenn Research Center, Cleveland, OH, United States
Experimental Tests of UltraFlex Array Designs in Low Earth Orbital and Geosynchronous Charging Environments
Galofaro, Joel T.; Vayner, Boris V.; Hillard, Grover B.; September 2011; In English; First Atmospheric and Space Environments Conference, 22-25 Jun. 2009, San Antonio, TX, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 644423.06.32.03.05.03
Report No.(s): NASA/TM-2011-216752; E-17328; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020260
The present ground based investigations give the first definitive look describing the expected on-orbit charging behavior of Orion UltraFlex array coupons in the Low Earth Orbital and Geosynchronous Environments. Furthermore, it is important to note that the LEO charging environment also applies to the International Space Station as well as to the lunar mission charging environments. The GEO charging environment includes the bounding case for all lunar orbital and lunar surface mission environments. The UltraFlex thin film photovoltaic array technology has been targeted to become the sole power system for life support and on-orbit power for the manned Aires Crew Exploration Vehicle. It is therefore, crucial to gain an understanding of the complex charging behavior to answer some of the basic performance and survivability issues in an attempt to ascertain that a single UltraFlex array design will be able to cope with the projected worst case LEO and GEO charging environments. Testing was limited to four array coupons, two coupons each from two different array manufactures, Emcore and Spectrolab. The layout of each array design is identical and varies only in the actual cell technology used. The individual array cells from each manufacturer have an antireflection layered coating and come in two different varieties either uncoated (only AR coating) or coated with a thin conducting ITO layer. The LEO Plasma tests revealed that all four coupons passed the arc threshold -120 V bias tests. GEO electron gun charging tests revealed that only front side area of ITO coated coupons passed tests. Only the Emcore AR array passed backside Stage 2 GEO Tests.
Author
SOLAR ARRAYS; FLEXIBILITY; ELASTIC PROPERTIES; ENVIRONMENTAL TESTS; EARTH ORBITAL ENVIRONMENTS; SPACECRAFT CHARGING; LOW EARTH ORBITS; GEOSYNCHRONOUS ORBITS
20110020262 NASA Glenn Research Center, Cleveland, OH, United States
Final Report: Fire Prevention, Detection, and Suppression Project, Exploration Technology Development Program
Ruff, Gary A.; September 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 344397,01,03
Report No.(s): NASA/TM-2011-217036; E-17742; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020262
The Fire Prevention, Detection, and Suppression (FPDS) project is a technology development effort within the Exploration Technology Development Program of the Exploration System Missions Directorate (ESMD) that addresses all aspects of fire safety aboard manned exploration systems. The overarching goal for work in the FPDS area is to develop technologies that will ensure crew health and safety on exploration missions by reducing the likelihood of a fire, or, if one does occur, minimizing the risk to the crew, mission, or system. This is accomplished by addressing the areas of (1) fire prevention and material flammability, (2) fire signatures and detection, and (3) fire suppression and response. This report describes the outcomes of this project from the formation of the Exploration Technology Development Program (ETDP) in October 2005 to September 31, 2010 when the Exploration Technology Development Program was replaced by the Enabling Technology Development and Demonstration Program. NASA s fire safety work will continue under this new program and will build upon the accomplishments described herein.
Author
DETECTION; FIRE PREVENTION; FIRES; SAFETY; FLAMMABILITY; SAFETY MANAGEMENT; FLAME RETARDANTS; FIREPROOFING
Additions to the NASA Aeronautics and Space Database as of 11/22/2011
20110020665 NASA Langley Research Center, Hampton, VA, United States
Composite Crew Module: Primary Structure
Kirsch, Michael T.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 869021.05.07.07.03
Report No.(s): NASA/TM-2011-217185; NESC-RP-06-0191; L-20085; NF1676L-13697; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020665
In January 2007, the NASA Administrator and Associate Administrator for the Exploration Systems Mission Directorate chartered the NASA Engineering and Safety Center to design, build, and test a full-scale crew module primary structure, using carbon fiber reinforced epoxy based composite materials. The overall goal of the Composite Crew Module project was to develop a team from the NASA family with hands-on experience in composite design, manufacturing, and testing in anticipation of future space exploration systems being made of composite materials. The CCM project was planned to run concurrently with the Orion project's baseline metallic design within the Constellation Program so that features could be compared and discussed without inducing risk to the overall Program. This report discusses the project management aspects of the project including team organization, decision making, independent technical reviews, and cost and schedule management approach.
Author
CONSTELLATION PROGRAM; COMPOSITE STRUCTURES; SPACECRAFT MODULES; COMPOSITE MATERIALS; FIBER COMPOSITES
20110020693 NASA Langley Research Center, Hampton, VA, United States
Loft: An Automated Mesh Generator for Stiffened Shell Aerospace Vehicles
Eldred, Lloyd B.; November 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.07.09.12.01
Report No.(s): NASA/TM-2011-217300; L-20034; NF1676L-12884; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020693
Loft is an automated mesh generation code that is designed for aerospace vehicle structures. From user input, Loft generates meshes for wings, noses, tanks, fuselage sections, thrust structures, and so on. As a mesh is generated, each element is assigned properties to mark the part of the vehicle with which it is associated. This property assignment is an extremely powerful feature that enables detailed analysis tasks, such as load application and structural sizing. This report is presented in two parts. The first part is an overview of the code and its applications. The modeling approach that was used to create the finite element meshes is described. Several applications of the code are demonstrated, including a Next Generation Launch Technology (NGLT) wing-sizing study, a lunar lander stage study, a launch vehicle shroud shape study, and a two-stage-to-orbit (TSTO) orbiter. Part two of the report is the program user manual. The manual includes in-depth tutorials and a complete command reference.
Author
AEROSPACE VEHICLES; GRID GENERATION (MATHEMATICS); AUTOMATIC CONTROL; COMPUTER PROGRAMS; SPACECRAFT MODELS; SPACECRAFT CONFIGURATIONS; STIFFNESS; SHELLS (STRUCTURAL FORMS)
Additions to the NASA Aeronautics and Space Database as of 11/24/2011
20110020812 NASA Langley Research Center, Hampton, VA, United States
Correctness Proof of a Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs
Malekpour, Mahyar R.; October 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 534723.02.02.07.30
Report No.(s): NASA/TM-2011-217184; L-20066; NF1676L-13421; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020812
This report presents a deductive proof of a self-stabilizing distributed clock synchronization protocol. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. This protocol does not rely on assumptions about the initial state of the system, and no central clock or a centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. We present a deductive proof of the correctness of the protocol as it applies to the networks with unidirectional and bidirectional links. We also confirm the claims of determinism and linear convergence.
Author
CLOCKS; SYNCHRONISM; PROVING; STABILIZATION; MESSAGES; PROTOCOL (COMPUTERS)
20110020830 NASA Glenn Research Center, Cleveland, OH, United States
Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio Part 1 Fan Stage Design and Experimental Results
Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.; October 2011; In English; Turbo Expo 2010, 14-18 Jun. 2010, Glasgow, Scotland, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.03.07
Report No.(s): NASA/TM-2011-216769/PART1; GT2010-22825; E-17395-1; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020830
NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.
Author
AERODYNAMIC CHARACTERISTICS; INLET FLOW; BYPASS RATIO; INLET TEMPERATURE; MACH NUMBER; MASS FLOW; PROPULSION SYSTEM CONFIGURATIONS
20110020831 NASA Glenn Research Center, Cleveland, OH, United States
Long-Duration Low-to Medium-Altitude Solar Electric Airship Concept
Bents, David J.; October 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 038957.04.06.03.03
Report No.(s): NASA/TM-2011-216815; E-17446; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020831
This report presents the conceptual design for a solar electric lighter-than-air, unmanned aerial vehicle, based on existing technology already reduced to practice, that could carry a 600-kg (1322-lbm) payload to altitudes up to 30 kft (9000 m), continuously maintain an airspeed up to 40 kt (21 m/sec), and remain in flight for up to 100 days. The design is based on modern nonrigid airship technology, high-strength polymer fabrics and barrier films, and previously demonstrated aerospace electrical power technology, including lightweight photovoltaics and hydrogen-air polymer electrolyte membrane (PEM) fuel cells. The vehicle concept exploits the inherent synergy between the use of hydrogen as a lifting gas and the use of hydrogen-air PEM fuel-cell technology for onboard solar energy storage. In this report, the air vehicle concept is physically characterized and its estimated performance envelope is defined
Author
PILOTLESS AIRCRAFT; AIRSHIPS; SOLAR ENERGY; PHOTOVOLTAIC CONVERSION; LOW ALTITUDE; ELECTRIC MOTOR VEHICLES; ENERGY STORAGE
20110020832 NASA Glenn Research Center, Cleveland, OH, United States
Super Cooled Large Droplet Analysis of Several Geometries Using LEWICE3D Version 3
Bidwell, Colin S.; October 2011; In English; Atmospheric and Space Environments Conference, 2-5 Aug. 2010, Toronto, Ontario, Canada; Original contains color illustrations
Contract(s)/Grant(s): WBS 457280.02.07.03.02.02
Report No.(s): NASA/TM-2011-216945; AIAA Paper 2010-7675; E-17549; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020832
Super Cooled Large Droplet (SLD) collection efficiency calculations were performed for several geometries using the LEWICE3D Version 3 software. The computations were performed using the NASA Glenn Research Center SLD splashing model which has been incorporated into the LEWICE3D Version 3 software. Comparisons to experiment were made where available. The geometries included two straight wings, a swept 64A008 wing tip, two high lift geometries, and the generic commercial transport DLR-F4 wing body configuration. In general the LEWICE3D Version 3 computations compared well with the 2D LEWICE 3.2.2 results and with experimental data where available.
Author
AIRCRAFT ICING; DROP SIZE; SPLASHING; AERODYNAMIC CONFIGURATIONS; SWEPT WINGS
20110020834 NASA Glenn Research Center, Cleveland, OH, United States
Lunar Surface Systems Supportability Technology Development Roadmap
Oeftering, Richard C.; Struk, Peter M.; Green, Jennifer L.; Chau, Savio N.; Curell, Philip C.; Dempsey, Cathy A.; Patterson, Linda P.; Robbins, William; Steele, Michael A.; DAnnunzio, Anthony; Meseroll, Robert; Quiter, John; Shannon, Russell; Easton, John W.; Madaras, Eric I.; BrownTaminger, Karen M.; Tabera, John T.; Tellado, Joseph; Williams, Marth K.; Zeitlin, Nancy P.; October 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 825855.01.03.03.03
Report No.(s): NASA/TM-2011-216957; E-17562; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020834
The Lunar Surface Systems Supportability Technology Development Roadmap is a guide for developing the technologies needed to enable the supportable, sustainable, and affordable exploration of the Moon and other destinations beyond Earth. Supportability is defined in terms of space maintenance, repair, and related logistics. This report considers the supportability lessons learned from NASA and the Department of Defense. Lunar Outpost supportability needs are summarized, and a supportability technology strategy is established to make the transition from high logistics dependence to logistics independence. This strategy will enable flight crews to act effectively to respond to problems and exploit opportunities in an environment of extreme resource scarcity and isolation. The supportability roadmap defines the general technology selection criteria. Technologies are organized into three categories: diagnostics, test, and verification; maintenance and repair; and scavenge and recycle. Furthermore, "embedded technologies" and "process technologies" are used to designate distinct technology types with different development cycles. The roadmap examines the current technology readiness level and lays out a four-phase incremental development schedule with selection decision gates. The supportability technology roadmap is intended to develop technologies with the widest possible capability and utility while minimizing the impact on crew time and training and remaining within the time and cost constraints of the program.
Author
LUNAR SURFACE; LUNAR BASES; DEFENSE PROGRAM; LOGISTICS; FLIGHT CREWS; EDUCATION; SPACE MAINTENANCE
20110020835 NASA Glenn Research Center, Cleveland, OH, United States
Radiation-Spray Coupling for Realistic Flow Configurations
El-Asrag, Hossam; Iannetti, Anthony C.; October 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.19.02
Report No.(s): NASA/TM-2011-217111; E-17787; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020835
Three Large Eddy Simulations (LES) for a lean-direct injection (LDI) combustor are performed and compared. In addition to the cold flow simulation, the effect of radiation coupling with the multi-physics reactive flow is analyzed. The flame let progress variable approach is used as a subgrid combustion model combined with a stochastic subgrid model for spray atomization and an optically thin radiation model. For accurate chemistry modeling, a detailed Jet-A surrogate mechanism is utilized. To achieve realistic inflow, a simple recycling technique is performed at the inflow section upstream of the swirler. Good comparison is shown with the experimental data mean and root mean square profiles. The effect of combustion is found to change the shape and size of the central recirculation zone. Radiation is found to change the spray dynamics and atomization by changing the heat release distribution and the local temperature values impacting the evaporation process. The simulation with radiation modeling shows wider range of droplet size distribution by altering the evaporation rate. The current study proves the importance of radiation modeling for accurate prediction in realistic spray combustion configurations, even for low pressure systems.
Author
LARGE EDDY SIMULATION; INJECTION; COMBUSTION PHYSICS; COMPUTATIONAL FLUID DYNAMICS; EVAPORATION RATE; MATHEMATICAL MODELS
20110020836 NASA Glenn Research Center, Cleveland, OH, United States
Two-Phase Cryogenic Heat Exchanger for the Thermodynamic Vent System
Christie, Robert J.; October 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 095240.04.13.01.14.01.03
Report No.(s): NASA/TM-2011-217220; E-17903; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020836
A two-phase cryogenic heat exchanger for a thermodynamic vent system was designed and analyzed, and the predicted performance was compared with test results. A method for determining the required size of the Joule-Thomson device was also developed. Numerous sensitivity studies were performed to show that the design was robust and possessed a comfortable capacity margin. The comparison with the test results showed very similar heat extraction performance for similar inlet conditions. It was also shown that estimates for Joule- Thomson device flow rates and exit quality can vary significantly and these need to be accommodated for with a robust system design.
Author
CRYOGENICS; HEAT EXCHANGERS; THERMODYNAMICS; SYSTEMS ENGINEERING; EXTRACTION; FLOW VELOCITY
20110020837 NASA Glenn Research Center, Cleveland, OH, United States
Development of an Open Rotor Cycle Model in NPSS Using a Multi-Design Point Approach
Hendricks, Eric S.; October 2011; In English; Turbo Expo 2011, 6-10 Jun. 2011, Vancouver, BC, Canada; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.13.11
Report No.(s): NASA/TM-2011-217225; GT2011-46694; E-17908; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020837
NASA's Environmentally Responsible Aviation Project and Subsonic Fixed Wing Project are focused on developing concepts and technologies which may enable dramatic reductions to the environmental impact of future generation subsonic aircraft (Refs. 1 and 2). The open rotor concept (also referred to as the Unducted Fan or advanced turboprop) may allow the achievement of this objective by reducing engine emissions and fuel consumption. To evaluate its potential impact, an open rotor cycle modeling capability is needed. This paper presents the initial development of an open rotor cycle model in the Numerical Propulsion System Simulation (NPSS) computer program which can then be used to evaluate the potential benefit of this engine. The development of this open rotor model necessitated addressing two modeling needs within NPSS. First, a method for evaluating the performance of counter-rotating propellers was needed. Therefore, a new counter-rotating propeller NPSS component was created. This component uses propeller performance maps developed from historic counter-rotating propeller experiments to determine the thrust delivered and power required. Second, several methods for modeling a counter-rotating power turbine within NPSS were explored. These techniques used several combinations of turbine components within NPSS to provide the necessary power to the propellers. Ultimately, a single turbine component with a conventional turbine map was selected. Using these modeling enhancements, an open rotor cycle model was developed in NPSS using a multi-design point approach. The multi-design point (MDP) approach improves the engine cycle analysis process by making it easier to properly size the engine to meet a variety of thrust targets throughout the flight envelope. A number of design points are considered including an aerodynamic design point, sea-level static, takeoff and top of climb. The development of this MDP model was also enabled by the selection of a simple power management scheme which schedules propeller blade angles with the freestream Mach number. Finally, sample open rotor performance results and areas for further model improvements are presented.
Author
CONTRAROTATING PROPELLERS; TURBINES; EXHAUST EMISSION; FLIGHT ENVELOPES; PROPELLER BLADES; PROPELLER EFFICIENCY; TAKEOFF; FUEL CONSUMPTION; AERODYNAMICS
20110020838 NASA Glenn Research Center, Cleveland, OH, United States
Development and Implementation of a Model-Driven Envelope Protection System for In-Flight Ice Contamination
Gingras, David R.; Barnhart, Billy P.; Martos, Borja; Ratvasky, Thomas P.; Morelli, Eugene; October 2011; In English; Guidance, Navigation, and Control Conference, 2-5 Aug. 2010, Toronto, Ontario, Canada; Original contains color illustrations
Contract(s)/Grant(s): NNX07AD58AWBS 645646.02.07.11.02
Report No.(s): NASA/TM-2011-216960; AIAA Paper 2010-8141; E-17565; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110020838
Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.
Author
AIRCRAFT PERFORMANCE; FLIGHT CHARACTERISTICS; AIRCRAFT ICING; ICE FORMATION
Additions to the NASA Aeronautics and Space Database as of 11/30/2011
20110022433 NASA Glenn Research Center, Cleveland, OH, United States
Aeronautical Mobile Airport Communications System (AeroMACS)
Budinger, James M.; Hall, Edward; October 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNC05CA85CWBS 031102.02.03.12.0677.11
Report No.(s): NASA/TM-2011-217236; E-17781-1; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022433
To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.
Author
MOBILE COMMUNICATION SYSTEMS; DATA ACQUISITION; DATA TRANSMISSION; AIRPORTS; WIRELESS COMMUNICATION; WIDEBAND COMMUNICATION; FREQUENCY DISTRIBUTION
20110022435 NASA Glenn Research Center, Cleveland, OH, United States
Review of Propulsion Technologies for N+3 Subsonic Vehicle Concepts
Ashcraft, Scott W.; Padron, Andres S.; Pascioni, Kyle A.; Stout, Gary W., Jr.; Huff, Dennis L.; October 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.11.01
Report No.(s): NASA/TM-2011-217239; E-17995; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022435
NASA has set aggressive fuel burn, noise, and emission reduction goals for a new generation (N+3) of aircraft targeting concepts that could be viable in the 2035 timeframe. Several N+3 concepts have been formulated, where the term "N+3" indicate aircraft three generations later than current state-of-the-art aircraft, "N". Dramatic improvements need to be made in the airframe, propulsion systems, mission design, and the air transportation system in order to meet these N+3 goals. The propulsion system is a key element to achieving these goals due to its major role with reducing emissions, fuel burn, and noise. This report provides an in-depth description and assessment of propulsion systems and technologies considered in the N+3 subsonic vehicle concepts. Recommendations for technologies that merit further research and development are presented based upon their impact on the N+3 goals and likelihood of being operational by 2035.
Author
PROPULSION SYSTEM CONFIGURATIONS; SYSTEMS ENGINEERING; PROPULSION SYSTEM PERFORMANCE; AIR TRANSPORTATION; AIRFRAMES
Additions to the NASA Aeronautics and Space Database as of 12/06/2011
20110022654 NASA Langley Research Center, Hampton, VA, United States
A Methodology for Evaluating Artifacts Produced by a Formal Verification Process
Siminiceanu, Radu I.; Miner, Paul S.; Person, Suzette; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNL09AA00AWBS 402600.04.04.04
Report No.(s): NASA/TM-2011-217193; L-20068; NF1676L-13467; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022654
The goal of this study is to produce a methodology for evaluating the claims and arguments employed in, and the evidence produced by formal verification activities. To illustrate the process, we conduct a full assessment of a representative case study for the Enabling Technology Development and Demonstration (ETDD) program. We assess the model checking and satisfiabilty solving techniques as applied to a suite of abstract models of fault tolerant algorithms which were selected to be deployed in Orion, namely the TTEthernet startup services specified and verified in the Symbolic Analysis Laboratory (SAL) by TTTech. To this end, we introduce the Modeling and Verification Evaluation Score (MVES), a metric that is intended to estimate the amount of trust that can be placed on the evidence that is obtained. The results of the evaluation process and the MVES can then be used by non-experts and evaluators in assessing the credibility of the verification results.
Author
PROGRAM VERIFICATION (COMPUTERS); FORMALISM; ETHERNET; FAULT TOLERANCE; ALGORITHMS; DESIGN ANALYSIS
20110022655 NASA Langley Research Center, Hampton, VA, United States
An Overview of a Trajectory-Based Solution for En Route and Terminal Area Self-Spacing to Include Parallel Runway Operations
Abbott, Terence S.; November 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNL10AA14BWBS 411931.02.61.07.01
Report No.(s): NASA/CR-2011-217194; NF1676L-13571; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022655
This paper presents an overview of an algorithm specifically designed to support NASA's Airborne Precision Spacing concept. This airborne self-spacing concept is trajectory-based, allowing for spacing operations prior to the aircraft being on a common path. This implementation provides the ability to manage spacing against two traffic aircraft, with one of these aircraft operating to a parallel dependent runway. Because this algorithm is trajectory-based, it also has the inherent ability to support required-time-of-arrival (RTA) operations
Author
ALGORITHMS; RUNWAYS; GENERAL OVERVIEWS; TRAJECTORIES; AIR TRANSPORTATION; AIRCRAFT APPROACH SPACING
20110022658 NASA Langley Research Center, Hampton, VA, United States
Inflow/Outflow Boundary Conditions with Application to FUN3D
Carlson, Jan-Renee; October 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.07.14.03
Report No.(s): NASA/TM-2011-217181; L-20011; NF1676L-12459; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022658
Several boundary conditions that allow subsonic and supersonic flow into and out of the computational domain are discussed. These boundary conditions are demonstrated in the FUN3D computational fluid dynamics (CFD) code which solves the three-dimensional Navier-Stokes equations on unstructured computational meshes. The boundary conditions are enforced through determination of the flux contribution at the boundary to the solution residual. The boundary conditions are implemented in an implicit form where the Jacobian contribution of the boundary condition is included and is exact. All of the flows are governed by the calorically perfect gas thermodynamic equations. Three problems are used to assess these boundary conditions. Solution residual convergence to machine zero precision occurred for all cases. The converged solution boundary state is compared with the requested boundary state for several levels of mesh densities. The boundary values converged to the requested boundary condition with approximately second-order accuracy for all of the cases.
Author
BOUNDARY CONDITIONS; COMPUTATIONAL FLUID DYNAMICS; COMPUTER PROGRAMS; THREE DIMENSIONAL FLOW; SUBSONIC FLOW; SUPERSONIC FLOW
20110022659 NASA Langley Research Center, Hampton, VA, United States
A State-of-the-Art Experimental Laboratory for Cloud and Cloud-Aerosol Interaction Research
Fremaux, Charles M.; Bushnell, Dennis M.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 432938.08.01.07.43
Report No.(s): NASA/TM-2011-217192; L-20045; NF1676L-13066; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022659
The state of the art for predicting climate changes due to increasing greenhouse gasses in the atmosphere with high accuracy is problematic. Confidence intervals on current long-term predictions (on the order of 100 years) are so large that the ability to make informed decisions with regard to optimum strategies for mitigating both the causes of climate change and its effects is in doubt. There is ample evidence in the literature that large sources of uncertainty in current climate models are various aerosol effects. One approach to furthering discovery as well as modeling, and verification and validation (V&V) for cloud-aerosol interactions is use of a large "cloud chamber" in a complimentary role to in-situ and remote sensing measurement approaches. Reproducing all of the complex interactions is not feasible, but it is suggested that the physics of certain key processes can be established in a laboratory setting so that relevant fluid-dynamic and cloud-aerosol phenomena can be experimentally simulated and studied in a controlled environment. This report presents a high-level argument for significantly improved laboratory capability, and is meant to serve as a starting point for stimulating discussion within the climate science and other interested communities.
Author
AEROSOLS; CLIMATE CHANGE; CLIMATE MODELS; REMOTE SENSING; CLOUDS (METEOROLOGY); GREENHOUSE EFFECT
20110022666 NASA Marshall Space Flight Center, Huntsville, AL, United States
Online Oxide Contamination Measurement and Purification Demonstration
Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.; October 2011; In English; Original contains color illustrations
Report No.(s): NASA/TP-2011-216473; M-1322; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110022666
Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.
Author
CONTAMINATION; OXIDES; PURIFICATION; SODIUM; POTASSIUM; FABRICATION; FISSION PRODUCTS; COOLING SYSTEMS; MECHANICAL ENGINEERING; CENTRIFUGAL PUMPS
Additions to the NASA Aeronautics and Space Database as of 12/12/2011
20110023003 NASA Langley Research Center, Hampton, VA, United States
Experimental and Analytical Evaluation of a Composite Honeycomb Deployable Energy Absorber
Jackson, Karen E.; Kellas, Sotirios; Horta, Lucas G.; Annett, Martin S.; Polanco, Michael A.; Littell, Justin D.; Fasanella, Edwin L.; November 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.07.05.02.01
Report No.(s): NASA/TM-2011-217301; L-20093; NF1676L-13518; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023003
In 2006, the NASA Subsonic Rotary Wing Aeronautics Program sponsored the experimental and analytical evaluation of an externally deployable composite honeycomb structure that is designed to attenuate impact energy during helicopter crashes. The concept, which is designated the Deployable Energy Absorber (DEA), utilizes an expandable Kevlar honeycomb structure to dissipate kinetic energy through crushing. The DEA incorporates a unique flexible hinge design that allows the honeycomb to be packaged and stowed flat until needed for deployment. A variety of deployment options such as linear, radial, and/or hybrid methods can be used. Experimental evaluation of the DEA utilized a building block approach that included material characterization testing of its constituent, Kevlar -129 fabric/epoxy, and flexural testing of single hexagonal cells. In addition, the energy attenuation capabilities of the DEA were demonstrated through multi-cell component dynamic crush tests, and vertical drop tests of a composite fuselage section, retrofitted with DEA blocks, onto concrete, water, and soft soil. During each stage of the DEA evaluation process, finite element models of the test articles were developed and simulations were performed using the explicit, nonlinear transient dynamic finite element code, LS-DYNA. This report documents the results of the experimental evaluation that was conducted to assess the energy absorption capabilities of the DEA.
Author
COMPOSITE STRUCTURES; HONEYCOMB STRUCTURES; ROTARY WINGS; SUBSONIC SPEED; AIRCRAFT ACCIDENTS; EXPANDABLE STRUCTURES; KINETIC ENERGY; ABSORBERS (MATERIALS); ENERGY ABSORPTION
Additions to the NASA Aeronautics and Space Database as of 12/15/2011
20110023248 NASA Langley Research Center, Hampton, VA, United States
Development and Application of Benchmark Examples for Mode II Static Delamination Propagation and Fatigue Growth Predictions
Krueger, Ronald; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNL09AA00AWBS 877868.02.07.07.05.01.01
Report No.(s): NASA/CR-2011-217305; NIA Report No. 2011-02; NF1676L-13009; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023248
The development of benchmark examples for static delamination propagation and cyclic delamination onset and growth prediction is presented and demonstrated for a commercial code. The example is based on a finite element model of an End-Notched Flexure (ENF) specimen. The example is independent of the analysis software used and allows the assessment of the automated delamination propagation, onset and growth prediction capabilities in commercial finite element codes based on the virtual crack closure technique (VCCT). First, static benchmark examples were created for the specimen. Second, based on the static results, benchmark examples for cyclic delamination growth were created. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Fourth, starting from an initially straight front, the delamination was allowed to grow under cyclic loading. The number of cycles to delamination onset and the number of cycles during delamination growth for each growth increment were obtained from the automated analysis and compared to the benchmark examples. Again, good agreement between the results obtained from the growth analysis and the benchmark results could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Selecting the appropriate input parameters, however, was not straightforward and often required an iterative procedure. Overall the results are encouraging, but further assessment for mixed-mode delamination is required.
Author
DELAMINATING; MATHEMATICAL MODELS; FATIGUE (MATERIALS); FLEXING; CRACK CLOSURE; STRESS PROPAGATION; STATIC LOADS
20110023249 NASA Langley Research Center, Hampton, VA, United States
Design, Optimization, and Evaluation of Integrally-Stiffened Al-2139 Panel with Curved Stiffeners
Havens, David; Shiyekar, Sandeep; Norris, Ashley; Bird, R. Keith; Kapania, Rakesh K.; Olliffe, Robert; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.07.15.15
Report No.(s): NASA/TM-2011-217308; L-20097; NF1676L-13724; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023249
A curvilinear stiffened panel was designed, manufactured, and tested in the Combined Load Test Fixture at NASA Langley Research Center. The panel is representative of a large wing engine pylon rib and was optimized for minimum mass subjected to three combined load cases. The optimization included constraints on web buckling, material yielding, crippling or local stiffener failure, and damage tolerance using a new analysis tool named EBF3PanelOpt. Testing was performed for the critical combined compression-shear loading configuration. The panel was loaded beyond initial buckling, and strains and out-of-plane displacements were extracted from a total of 20 strain gages and 6 linear variable displacement transducers. The VIC-3D system was utilized to obtain full field displacements/strains in the stiffened side of the panel. The experimental data were compared with the strains and out-of-plane deflections from a high fidelity nonlinear finite element analysis. The experimental data were also compared with linear elastic finite element results of the panel/test-fixture assembly. Overall, the panel buckled very near to the predicted load in the web regions.
Author
DESIGN OPTIMIZATION; LOAD TESTS; TOLERANCES (MECHANICS); PANELS; STIFFENING; CURVATURE; LOADS (FORCES)
20110023250 NASA Langley Research Center, Hampton, VA, United States; Boeing Co., Huntington Beach, CA, United States
Blended Wing Body Concept Development with Open Rotor Engine Intergration
Pitera, David M.; DeHaan, Mark; Brown, Derrell; Kawai, Ronald T.; Hollowell, Steve; Camacho, Peter; Bruns, David; Rawden, Blaine K.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNL10AA05BWBS 699959.02.10.07.01
Report No.(s): NASA/CR-2011-217303; NF1676L-13758; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023250
The purpose of this study is to perform a systems analysis of a Blended Wing Body (BWB) open rotor concept at the conceptual design level. This concept will be utilized to estimate overall noise and fuel burn performance, leveraging recent test data. This study will also investigate the challenge of propulsion airframe installation of an open rotor engine on a BWB configuration. Open rotor engines have unique problems relative to turbofans. The rotors are open, exposed to flow conditions outside of the engine. The flow field that the rotors are immersed in may be higher than the free stream flow and it may not be uniform, both of these characteristics could increase noise and decrease performance. The rotors sometimes cause changes in the flow conditions imposed on aircraft surfaces. At high power conditions such as takeoff and climb out, the stream tube of air that goes through the rotors contracts rapidly causing the boundary layer on the body upper surface to go through an adverse pressure gradient which could result with separated airflow. The BWB / Open Rotor configuration must be designed to mitigate these problems.
Author
BLENDED-WING-BODY CONFIGURATIONS; ROTOR DYNAMICS; COMPUTATIONAL FLUID DYNAMICS; SYSTEMS ANALYSIS; AEROACOUSTICS; ENGINE AIRFRAME INTEGRATION
Additions to the NASA Aeronautics and Space Database as of 12/20/2011
20110023423 NASA Langley Research Center, Hampton, VA, United States
Piloted Simulation to Evaluate the Utility of a Real Time Envelope Protection System for Mitigating In-Flight Icing Hazards
Ranaudo, Richard J.; Martos, Borja; Norton, Bill W.; Gingras, David R.; Barnhart, Billy P.; Ratvasky, Thomas P.; Morelli, Eugene; October 2011; In English; Atmospheric and Space Environments Conference, 2-5 Aug. 2010, Toronto, Ontario, Canada; Original contains color illustrations
Contract(s)/Grant(s): NNX07AD58AWBS 645846,02.07.11.02
Report No.(s): NASA/TM-2011-216951; AIAA Paper 2010-7987; E-17556; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023423
The utility of the Icing Contamination Envelope Protection (ICEPro) system for mitigating a potentially hazardous icing condition was evaluated by 29 pilots using the NASA Ice Contamination Effects Flight Training Device (ICEFTD). ICEPro provides real time envelope protection cues and alerting messages on pilot displays. The pilots participating in this test were divided into two groups; a control group using baseline displays without ICEPro, and an experimental group using ICEPro driven display cueing. Each group flew identical precision approach and missed approach procedures with a simulated failure case icing condition. Pilot performance, workload, and survey questionnaires were collected for both groups of pilots. Results showed that real time assessment cues were effective in reducing the number of potentially hazardous upset events and in lessening exposure to loss of control following an incipient upset condition. Pilot workload with the added ICEPro displays was not measurably affected, but pilot opinion surveys showed that real time cueing greatly improved their situation awareness of a hazardous aircraft state.
Author
AIRCRAFT ICING; ICE FORMATION; FLIGHT TRAINING; REAL TIME OPERATION; PILOT PERFORMANCE; HAZARDS; ICE
20110023425 NASA Glenn Research Center, Cleveland, OH, United States
Advanced Stirling Convertor (ASC-E2) Performance Testing at NASA Glenn Research Center
Oriti, Salvatore; Wilson, Scott; November 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.05.02.04.02
Report No.(s): NASA/TM-2011-217102; NETS-2011-3496; E-17610-1; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023425
The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG Project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, four pairs of ASCs capable of operating to 850 C and designated with the model number ASC-E2, were delivered by Sunpower of Athens, Ohio, to GRC in 2010. The ASC-E2s underwent a series of tests that included workmanship vibration testing, performance mapping, and extended operation. Workmanship vibration testing was performed following fabrication of each convertor to verify proper hardware build. Performance mapping consisted of operating each convertor at various conditions representing the range expected during a mission. Included were conditions representing beginning-of-mission (BOM), end-of-mission (EOM), and fueling. This same series of tests was performed by Sunpower prior to ASC-E2 delivery. The data generated during the GRC test were compared to performance before delivery. Extended operation consisted of a 500-hr period of operation with conditions maintained at the BOM point. This was performed to demonstrate steady convertor performance following performance mapping. Following this initial 500-hr period, the ASC-E2s will continue extended operation, controller development and special durability testing, during which the goal is to accumulate tens of thousands of hours of operation. Data collected during extended operation will support reliability analysis. Performance data from these tests is summarized in this paper.
Author
STIRLING CYCLE; RELIABILITY ANALYSIS; PERFORMANCE TESTS; DURABILITY
20110023426 NASA Glenn Research Center, Cleveland, OH, United States
Natural Convection Cooling of the Advanced Stirling Radioisotope Generator Engineering Unit
Lewandowski, Edward J.; Hill, Dennis; November 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.05.02.04.02
Report No.(s): NASA/TM-2011-217101; NETS-2011-3609; E-17609; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023426
After fueling and prior to launch, the Advanced Stirling Radioisotope Generator (ASRG) will be stored for a period of time then moved to the launch pad for integration with the space probe and mounting on the launch vehicle. During this time, which could be as long as 3 years, the ASRG will operate continuously with heat rejected from the housing and fins. Typically, the generator will be cooled by forced convection using fans. During some of the ground operations, maintaining forced convection may add significant complexity, so allowing natural convection may simplify operations. A test was conducted on the ASRG Engineering Unit (EU) to quantify temperatures and operating parameters with natural convection only and determine if the EU could be safely operated in such an environment. The results show that with natural convection cooling the ASRG EU Stirling convertor pressure vessel temperatures and other parameters had significant margins while the EU was operated for several days in this configuration. Additionally, an update is provided on ASRG EU testing at NASA Glenn Research Center, where the ASRG EU has operated for over 16,000 hr and underwent extensive testing.
Author
STIRLING CYCLE; GROUND OPERATIONAL SUPPORT SYSTEM; PRESSURE VESSELS; FREE CONVECTION; FORCED CONVECTION; FINS; LAUNCH VEHICLES
20110023427 NASA Glenn Research Center, Cleveland, OH, United States
Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) Via the Multiscale Generalized Method of Cells
Liu, Kuang C.; Arnold, Steven M.; November 2011; In English; 35th International Conference and Exposition on Advanced Ceramics and Composites (ICACC 2011), 23-28 Jan. 2011, Daytona Beach, FL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 031102.02.02.03.0249.11
Report No.(s): NASA/TM-2011-217011; E-17674; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023427
It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.
Author
CERAMIC MATRIX COMPOSITES; MICROSTRUCTURE; MATRIX MATERIALS; STRESS-STRAIN RELATIONSHIPS
20110023429 NASA Glenn Research Center, Cleveland, OH, United States
Peak Satellite-to-Earth Data Rates Derived From Measurements of a 20 Gbps Bread-Board Modem
Landon, David G.; Simons, Rainee N.; Wintucky, Edwin G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen A.; McIntire, William K.; Metz, John L.; Smith, Francis J.; November 2011; In English; MILCOM 2011, 7-10 Nov. 2011, Baltimore, MD, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 432938.11.01.03.02.02.15
Report No.(s): NASA/TM-2011-217241; E-17997; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023429
A prototype data link using a Ka-band space qualified, high efficiency 200 W TWT amplifier and a bread-board modem emulator were created to explore the feasibility of very high speed communications in satellite-to-earth applications. Experiments were conducted using a DVB-S2-like waveform with modifications to support up to 20 Gbps through the addition of 128-Quadrature Amplitude Modulation (QAM). Limited by the bandwidth of the amplifier, a constant peak symbol rate of 3.2 Giga-symbols/sec was selected and the modulation order was varied to explore what peak data rate might be supported by an RF link through this amplifier. Using 128-QAM, an implementation loss of 3 dB was observed at 20 Gbps, and the loss decreased as data rate or bandwidth were reduced. Building on this measured data, realistic link budget calculations were completed. Low-Earth orbit (LEO) missions based on this TWTA with reasonable hardware assumptions and antenna sizing are found to be bandwidth-limited, rather than power-limited, making the spectral efficiency of 9/10-rate encoded 128-QAM very attractive. Assuming a bandwidth allocation of 1 GHz, these computations indicate that low-Earth orbit vehicles could achieve data rates up to 5 Gbps-an order of magnitude beyond the current state-of-practice, yet still within the processing power of a current FPGA-based software-defined modem. The measured performance results and a description of the experimental setup are presented to support these conclusions.
Author
TRAVELING WAVE AMPLIFIERS; COMMUNICATION SATELLITES; EXTREMELY HIGH FREQUENCIES; FIELD-PROGRAMMABLE GATE ARRAYS; QUADRATURE AMPLITUDE MODULATION; RATES (PER TIME); RADIO FREQUENCIES
20110023431 NASA Glenn Research Center, Cleveland, OH, United States
Advanced Technology Subsonic Transport Study: N+3 Technologies and Design Concepts
Raymer, Daniel P.; Wilson, Jack; Perkins, H. Douglas; Rizzi, Arthur; Zhang, Mengmeng; RamirezPuentes, Alfredo; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNC08VF71PWBS 561581.02.08.03.13.05
Report No.(s): NASA/TM-2011-217130; E-17819; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023431
Conceptual Research Corporation, the Science of the Possible, has completed a two-year study of concepts and technologies for future airliners in the 180-passenger class. This NASA-funded contract was primarily focused on the ambitious goal of a 70 percent reduction in fuel consumption versus the market-dominating Boeing 737-800. The study is related to the N+3 contracts awarded in 2008 by NASA s Aeronautics Research Mission Directorate to teams led by Boeing, GE Aviation, MIT, and Northrop Grumman, but with more modest goals and funding. CRC s contract featured a predominant emphasis on propulsion and fuel consumption, but since fuel consumption depends upon air vehicle design as much as on propulsion technology, the study included notional vehicle design, analysis, and parametric studies. Other NASA goals including NOx and noise reduction are of long-standing interest but were not highlighted in this study, other than their inclusion in the propulsion system provided to CRC by NASA. The B-737-800 was used as a benchmark, parametric tool, and design point of departure. It was modeled in the RDS-Professional aircraft design software then subjected to extensive parametric variations of parasitic drag, drag-due-to-lift, specific fuel consumption, and unsized empty weight. These studies indicated that the goal of a 70 percent reduction in fuel consumption could be attained with roughly a 30 percent improvement in all four parameters. The results were then fit to a Response Surface and coded for ease of use in subsequent trade studies. Potential technologies to obtain such savings were identified and discussed. More than 16 advanced concept designs were then prepared, attempting to investigate almost every possible emerging concept for application to this class airliner. A preliminary assessment of these concepts was done based on their total wetted area after design normalization of trimmed maximum lift. This assessment points towards a Tailless Airliner concept which was designed and analyzed in some detail. To make it work, a retracting canard and an all-moving chin rudder were employed, along with the use of the Active Aeroelastic Wing technology. Results indicate that a 60 percent savings in fuel burn may be credibly attained, but this depends upon a lot of technology maturation, concept development, and risk reduction. This should be expected-such a dramatic reduction in fuel consumption is a "game changer" in the world of commercial aviation. It won t be easy.
Author
BOEING 737 AIRCRAFT; TRANSPORT AIRCRAFT; CANARD CONFIGURATIONS; COMMERCIAL AIRCRAFT; DESIGN ANALYSIS; FUEL CONSUMPTION; NOISE REDUCTION; SUBSONIC SPEED; AEROELASTICITY
20110023432 QinetiQ North America, Cleveland, OH, United States
Software Users Manual (SUM): Extended Testability Analysis (ETA) Tool
Maul, William A.; Fulton, Christopher E.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNC06BA07B
Report No.(s): NASA/CR-2011-217240; E-17996; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023432
This software user manual describes the implementation and use the Extended Testability Analysis (ETA) Tool. The ETA Tool is a software program that augments the analysis and reporting capabilities of a commercial-off-the-shelf (COTS) testability analysis software package called the Testability Engineering And Maintenance System (TEAMS) Designer. An initial diagnostic assessment is performed by the TEAMS Designer software using a qualitative, directed-graph model of the system being analyzed. The ETA Tool utilizes system design information captured within the diagnostic model and testability analysis output from the TEAMS Designer software to create a series of six reports for various system engineering needs. The ETA Tool allows the user to perform additional studies on the testability analysis results by determining the detection sensitivity to the loss of certain sensors or tests. The ETA Tool was developed to support design and development of the NASA Ares I Crew Launch Vehicle. The diagnostic analysis provided by the ETA Tool was proven to be valuable system engineering output that provided consistency in the verification of system engineering requirements. This software user manual provides a description of each output report generated by the ETA Tool. The manual also describes the example diagnostic model and supporting documentation - also provided with the ETA Tool software release package - that were used to generate the reports presented in the manual
Author
SYSTEMS ENGINEERING; USER MANUALS (COMPUTER PROGRAMS); APPLICATIONS PROGRAMS (COMPUTERS); COMMERCIAL OFF-THE-SHELF PRODUCTS; GRAPH THEORY
20110023434 NASA Glenn Research Center, Cleveland, OH, United States
Lateral Load Testing of the Advanced Stirling Convertor (ASC-E2) Heater Head
Cornell, Peggy A.; Krause, David L.; Davis, Glen; Robbie, Malcolm G.; Gubics, David A.; November 2011; In English; 8th International Energy Conversion Engineering Conference (IECEC), 28-5-28 Jul. 2010, Nashville, TN, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.05.02.04.01
Report No.(s): NASA/TM-2011-217103; AIAA Paper 2010-6692; E-17727-1; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023434
Free-piston Stirling convertors are fundamental to the development of NASA s next generation of radioisotope power system, the Advanced Stirling Radioisotope Generator (ASRG). The ASRG will use General Purpose Heat Source (GPHS) modules as the energy source and Advanced Stirling Convertors (ASCs) to convert heat into electrical energy, and is being developed by Lockheed Martin under contract to the Department of Energy. Achieving flight status mandates that the ASCs satisfy design as well as flight requirements to ensure reliable operation during launch. To meet these launch requirements, GRC performed a series of quasi-static mechanical tests simulating the pressure, thermal, and external loading conditions that will be experienced by an ASC-E2 heater head assembly. These mechanical tests were collectively referred to as "lateral load tests" since a primary external load lateral to the heater head longitudinal axis was applied in combination with the other loading conditions. The heater head was subjected to the operational pressure, axial mounting force, thermal conditions, and axial and lateral launch vehicle acceleration loadings. To permit reliable prediction of the heater head s structural performance, GRC completed Finite Element Analysis (FEA) computer modeling for the stress, strain, and deformation that will result during launch. The heater head lateral load test directly supported evaluation of the analysis and validation of the design to meet launch requirements. This paper provides an overview of each element within the test and presents assessment of the modeling as well as experimental results of this task.
Author
STIRLING CYCLE; RADIOISOTOPE HEAT SOURCES; PISTON ENGINES; LOAD TESTS; LAUNCH VEHICLES; STATIC TESTS
20110023436 NASA Glenn Research Center, Cleveland, OH, United States
Numerical Studies of an Array of Fluidic Diverter Actuators for Flow Control
Gokoglu, Suleyman A.; Kuczmarski, Maria A.; Culley, Dennis E.; Raghu, Surya; November 2011; In English; 41st Fluid Dynamics Conference and Exhibit, 27-30 Jun. 2011, Honolulu, HI, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.17.13.01
Report No.(s): NASA/TM-2011-217259; AIAA Paper 2011-3100; E-18014; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023436
In this paper, we study the effect of boundary conditions on the behavior of an array of uniformly-spaced fluidic diverters with an ultimate goal to passively control their output phase. This understanding will aid in the development of advanced designs of actuators for flow control applications in turbomachinery. Computations show that a potential design is capable of generating synchronous outputs for various inlet boundary conditions if the flow inside the array is initiated from quiescence. However, when the array operation is originally asynchronous, several approaches investigated numerically demonstrate that re-synchronization of the actuators in the array is not practical since it is very sensitive to asymmetric perturbations and imperfections. Experimental verification of the insights obtained from the present study is currently being pursued.
Author
ACTUATORS; BOUNDARY CONDITIONS; TURBOMACHINERY; FLUIDICS; SYNCHRONISM; PERTURBATION
20110023439 NASA Glenn Research Center, Cleveland, OH, United States
An Evaluation of Performance Metrics for High Efficiency Tube-and-Wing Aircraft Entering Service in 2030 to 2035
Perkins, H. Douglas; Wilson, Jack; Raymer, Daniel P.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 599489.02.07.03.03.12.02
Report No.(s): NASA/TM-2011-217264; E-18020; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023439
An analysis of basic vehicle characteristics required to meet the Fundamental Aeronautics Program s 70 percent energy consumption reduction goal for commercial airliners in the 2030 to 2035 timeframe was conducted. A total of 29 combinations of vehicle parasitic drag coefficient, vehicle induced drag coefficient, vehicle empty weight and engine Specific Fuel Consumption were used to create sized tube-and-wing vehicle models. The mission fuel burn for each of these sized vehicles was then compared to a baseline current technology vehicle. A response surface equation was generated of fuel burn reduction as a function of the four basic vehicle performance metrics, so that any values of the performance metrics up to a 50 percent reduction could be used to estimate fuel burn reduction of tube-and-wing aircraft for future studies.
Author
AERODYNAMIC COEFFICIENTS; COMMERCIAL AIRCRAFT; ENERGY CONSUMPTION; FUEL CONSUMPTION; AERODYNAMIC DRAG; INDUCED DRAG
Additions to the NASA Aeronautics and Space Database as of 12/26/2011
20110023619 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Failure Assessment Diagram for Titanium Brazed Joints
Flom, Yury; Jones, Justin S.; Powell, Mollie M.; Puckett, David F.; October 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-215882; GSFC.TM.5341.2011; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023619
The interaction equation was used to predict failure in Ti-4V-6Al joints brazed with Al 1100 filler metal. The joints used in this study were geometrically similar to the joints in the brazed beryllium metering structure considered for the ATLAS telescope. This study confirmed that the interaction equation R(sub sigma) + R(sub Tau) = 1, where R(sub sigma) and R(sub Tau)are normal and shear stress ratios, can be used as conservative lower bound estimate of the failure criterion in ATLAS brazed joints as well as for construction of the Failure Assessment Diagram (FAD).
Author
BRAZING; SOLDERED JOINTS; TITANIUM; STRUCTURAL FAILURE; FAILURE ANALYSIS
20110023620 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Requirements for an Advanced Ocean Radiometer
Meister, Gerhard; McClain, Charles R.; Ahmad, Ziauddin; Bailey, Sean W.; Barnes, Robert A.; Brown, Steven; Eplee, Robert E.; Franz, Bryan; Holmes, Alan; Monosmith, W. Bryan; Patt, Frederick S.; Stumpf, Richard P.; Turpie, Kevin R.; Werdell, P. Jeremy; October 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-215883; GSFC.TM.5375.2011; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023620
This document suggests requirements for an advanced ocean radiometer, such as e.g. the ACE (Aerosol/Cloud/Ecosystem) ocean radiometer. The ACE ocean biology mission objectives have been defined in the ACE Ocean Biology white paper. The general requirements presented therein were chosen as the basis for the requirements provided in this document, which have been transformed into specific, testable requirements. The overall accuracy goal for the advanced ocean radiometer is that the total radiometric uncertainties are 0.5% or smaller for all bands. Specific mission requirements of SeaWiFS, MODIS, and VIIRS were often used as a model for the requirements presented here, which are in most cases more demanding than the heritage requirements. Experience with on-orbit performance and calibration (from SeaWiFS and MODIS) and prelaunch testing (from SeaWiFS, MODIS, and VIIRS) were important considerations when formulating the requirements. This document describes requirements in terms of the science data products, with a focus on qualities that can be verified by prelaunch radiometric characterization. It is expected that a more comprehensive requirements document will be developed during mission formulation
Author
OCEANS; MODIS (RADIOMETRY); SEA-VIEWING WIDE FIELD-OF-VIEW SENSOR; CALIBRATING; PERFORMANCE TESTS; IMAGING SPECTROMETERS; RADIOMETERS
20110023650 NASA Langley Research Center, Hampton, VA, United States
An In-Depth Tutorial on Constitutive Equations for Elastic Anisotropic Materials
Nemeth, Michael P.; December 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 869021.04.07.01.13
Report No.(s): NASA/TM-2011-217314; L-20083; NF1676L-13690; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023650
An in-depth tutorial on the constitutive equations for elastic, anisotropic materials is presented. Basic concepts are introduced that are used to characterize materials, and notions about how anisotropic material deform are presented. Hooke s law and the Duhamel-Neuman law for isotropic materials are presented and discussed. Then, the most general form of Hooke s law for elastic anisotropic materials is presented and symmetry requirements are given. A similar presentation is also given for the generalized Duhamel-Neuman law for elastic, anisotropic materials that includes thermal effects. Transformation equations for stress and strains are presented and the most general form of the transformation equations for the constitutive matrices are given. Then, specialized transformation equations are presented for dextral rotations about the coordinate axes. Next, concepts of material symmetry are introduced and criteria for material symmetries are presented. Additionally, engineering constants of fully anisotropic, elastic materials are derived from first principles and the specialized to several cases of practical importance.
Author
CONSTITUTIVE EQUATIONS; ANISOTROPY; TEMPERATURE EFFECTS; HOOKES LAW; AXES (REFERENCE LINES)
20110023654 NASA Langley Research Center, Hampton, VA, United States
Discretely Conservative Finite-Difference Formulations for Nonlinear Conservation Laws in Split Form: Theory and Boundary Conditions
Fisher, Travis C.; Carpenter, Mark H.; Nordstroem, Jan; Yamaleev, Nail K.; Swanson, R. Charles; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNX09AV08A; W911NF-06-R-006WBS 599489.02.07.07.03.13.01
Report No.(s): NASA/TM-2011-217307; L-20084; NF1676L-13679; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023654
Simulations of nonlinear conservation laws that admit discontinuous solutions are typically restricted to discretizations of equations that are explicitly written in divergence form. This restriction is, however, unnecessary. Herein, linear combinations of divergence and product rule forms that have been discretized using diagonal-norm skew-symmetric summation-by-parts (SBP) operators, are shown to satisfy the sufficient conditions of the Lax-Wendroff theorem and thus are appropriate for simulations of discontinuous physical phenomena. Furthermore, special treatments are not required at the points that are near physical boundaries (i.e., discrete conservation is achieved throughout the entire computational domain, including the boundaries). Examples are presented of a fourth-order, SBP finite-difference operator with second-order boundary closures. Sixth- and eighth-order constructions are derived, and included in E. Narrow-stencil difference operators for linear viscous terms are also derived; these guarantee the conservative form of the combined operator.
Author
BOUNDARY CONDITIONS; CONSERVATION LAWS; FINITE DIFFERENCE THEORY; NONLINEARITY; SIMULATION; DISCRETIZATION (MATHEMATICS); NUMERICAL STABILITY
20110023655 NASA Langley Research Center, Hampton, VA, United States
Dynamic Shape Reconstruction of Three-Dimensional Frame Structures Using the Inverse Finite Element Method
Gherlone, Marco; Massimiliano, Priscilla Cerracchio; Mattone, Massimiliano; DiSciuva, Marco; December 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 284848.02.03.07.01
Report No.(s): NASA/TP-2011-217315; L-20096; NF1676L-13844; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023655
A robust and efficient computational method for reconstructing the three-dimensional displacement field of truss, beam, and frame structures, using measured surface-strain data, is presented. Known as shape sensing , this inverse problem has important implications for real-time actuation and control of smart structures, and for monitoring of structural integrity. The present formulation, based on the inverse Finite Element Method (iFEM), uses a least-squares variational principle involving strain measures of Timoshenko theory for stretching, torsion, bending, and transverse shear. Two inverse-frame finite elements are derived using interdependent interpolations whose interior degrees-of-freedom are condensed out at the element level. In addition, relationships between the order of kinematic-element interpolations and the number of required strain gauges are established. As an example problem, a thin-walled, circular cross-section cantilevered beam subjected to harmonic excitations in the presence of structural damping is modeled using iFEM; where, to simulate strain-gauge values and to provide reference displacements, a high-fidelity MSC/NASTRAN shell finite element model is used. Examples of low and high-frequency dynamic motion are analyzed and the solution accuracy examined with respect to various levels of discretization and the number of strain gauges.
Author
FINITE ELEMENT METHOD; STRUCTURAL FAILURE; VARIATIONAL PRINCIPLES; DYNAMIC STRUCTURAL ANALYSIS; REAL TIME OPERATION; SMART STRUCTURES; TRANSVERSE LOADS; VIBRATION DAMPING; DISPLACEMENT; KINEMATICS
Additions to the NASA Aeronautics and Space Database as of 12/27/2011
20110023668 NASA Langley Research Center, Hampton, VA, United States
Autonomous Flight Rules - A Concept for Self-Separation in U.S. Domestic Airspace
Wing, David J.; Cotton, William B.; November 2011; In English
Contract(s)/Grant(s): WBS 411931.02.51.07.01
Report No.(s): NASA/TP-2011-217174; L-20058; NF1676L-12830; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023668
Autonomous Flight Rules (AFR) are proposed as a new set of operating regulations in which aircraft navigate on tracks of their choice while self-separating from traffic and weather. AFR would exist alongside Instrument and Visual Flight Rules (IFR and VFR) as one of three available flight options for any appropriately trained and qualified operator with the necessary certified equipment. Historically, ground-based separation services evolved by necessity as aircraft began operating in the clouds and were unable to see each other. Today, technologies for global navigation, airborne surveillance, and onboard computing enable the functions of traffic conflict management to be fully integrated with navigation procedures onboard the aircraft. By self-separating, aircraft can operate with more flexibility and fewer restrictions than are required when using ground-based separation. The AFR concept is described in detail and provides practical means by which self-separating aircraft could share the same airspace as IFR and VFR aircraft without disrupting the ongoing processes of Air Traffic Control.
Author
AIRSPACE; AUTONOMY; FLIGHT RULES; COLLISION AVOIDANCE; AIRCRAFT GUIDANCE; FLIGHT CONTROL; FLIGHT SAFETY; AUTONOMOUS NAVIGATION; SPACING
20110023677 NASA Langley Research Center, Hampton, VA, United States
Space Transportation System (STS)-133/External Tank (ET)-137 Intertank (IT) Stringer Cracking Issue and Repair Assessment: Proximate Cause Determination and Material Characterization Study
Piascik, Robert S.; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 869021.05.07.04.12
Report No.(s): NASA/TM-2011-217318; NESC-RP-10-00680; L-20106; NF1676L-13970; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023677
Several cracks were detected in stringers located beneath the foam on the External Tank (ET) following the launch scrub of Space Transportation System (STS)-133 on November 5, 2010. The stringer material was aluminum-lithium (AL-Li) 2090-T83 fabricated from sheets that were nominally 0.064 inches thick. The mechanical properties of the stringer material were known to vary between different material lots, with the stringers from ET-137 (predominately lots 620853 and 620854) having the highest yield and ultimate stresses. Subsequent testing determined that these same lots also had the lowest fracture toughness properties. The NASA Engineering and Safety Center (NESC) supported the Space Shuttle Program (SSP)-led investigation. The objective of this investigation was to develop a database of test results to provide validation for structural analysis models, independently confirm test results obtained from other investigators, and determine the proximate cause of the anomalous low fracture toughness observed in stringer lots 620853 and 620854. This document contains the outcome of the investigation.
Author
CHARACTERIZATION; CRACKS; EXTERNAL TANKS; MECHANICAL PROPERTIES; SPACE TRANSPORTATION SYSTEM; STRINGERS; DISCOVERY (ORBITER); FABRICATION
20110023685 NASA Marshall Space Flight Center, Huntsville, AL, United States
Advanced X-Ray Timing Array Mission: Conceptual Spacecraft Design Study
Hopkins, R. C.; Johnson, L.; Thomas, H. D.; Wilson-Hodge, C. A.; Baysinger, M.; Maples, C. D.; Fabisinski, L.L.; Hornsby, L.; Thompson, K. S.; Miernik, J. H.; November 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-216476; M-1325; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023685
The Advanced X-Ray Timing Array (AXTAR) is a mission concept for submillisecond timing of bright galactic x-ray sources. The two science instruments are the Large Area Timing Array (LATA) (a collimated instrument with 2-50-keV coverage and over 3 square meters of effective area) and a Sky Monitor (SM), which acts as a trigger for pointed observations of x-ray transients. The spacecraft conceptual design team developed two spacecraft concepts that will enable the AXTAR mission: A minimal configuration to be launched on a Taurus II and a larger configuration to be launched on a Falcon 9 or similar vehicle.
Author
BLACK HOLES (ASTRONOMY); NEUTRON STARS; MISSION PLANNING; SPACECRAFT DESIGN; X RAY SOURCES
20110023688 NASA Glenn Research Center, Cleveland, OH, United States
The NASA Subsonic Jet Particle Image Velocimetry (PIV) Dataset
Bridges, James; Wernet, Mark P.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.17.03
Report No.(s): NASA/TM-2011-216807; E-17439; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023688
Many tasks in fluids engineering require prediction of turbulence of jet flows. The present document documents the single-point statistics of velocity, mean and variance, of cold and hot jet flows. The jet velocities ranged from 0.5 to 1.4 times the ambient speed of sound, and temperatures ranged from unheated to static temperature ratio 2.7. Further, the report assesses the accuracies of the data, e.g., establish uncertainties for the data. This paper covers the following five tasks: (1) Document acquisition and processing procedures used to create the particle image velocimetry (PIV) datasets. (2) Compare PIV data with hotwire and laser Doppler velocimetry (LDV) data published in the open literature. (3) Compare different datasets acquired at the same flow conditions in multiple tests to establish uncertainties. (4) Create a consensus dataset for a range of hot jet flows, including uncertainty bands. (5) Analyze this consensus dataset for self-consistency and compare jet characteristics to those of the open literature. The final objective was fulfilled by using the potential core length and the spread rate of the half-velocity radius to collapse of the mean and turbulent velocity fields over the first 20 jet diameters.
Author
COMPUTATIONAL FLUID DYNAMICS; GAS JETS; SUBSONIC FLOW; TURBULENCE; PARTICLE IMAGE VELOCIMETRY; LASER DOPPLER VELOCIMETERS; ACOUSTIC VELOCITY
20110023701 NASA Glenn Research Center, Cleveland, OH, United States
Reliability Based Design for a Raked Wing Tip of an Airframe
Patnaik, Surya N.; Pai, Shantaram S.; Coroneos, Rula M.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.13.05
Report No.(s): NASA/TM-2011-216808; E-17440; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023701
A reliability-based optimization methodology has been developed to design the raked wing tip of the Boeing 767-400 extended range airliner made of composite and metallic materials. Design is formulated for an accepted level of risk or reliability. The design variables, weight and the constraints became functions of reliability. Uncertainties in the load, strength and the material properties, as well as the design variables, were modeled as random parameters with specified distributions, like normal, Weibull or Gumbel functions. The objective function and constraint, or a failure mode, became derived functions of the risk-level. Solution to the problem produced the optimum design with weight, variables and constraints as a function of the risk-level. Optimum weight versus reliability traced out an inverted-S shaped graph. The center of the graph corresponded to a 50 percent probability of success, or one failure in two samples. Under some assumptions, this design would be quite close to the deterministic optimum solution. The weight increased when reliability exceeded 50 percent, and decreased when the reliability was compromised. A design could be selected depending on the level of risk acceptable to a situation. The optimization process achieved up to a 20-percent reduction in weight over traditional design.
Author
COMPOSITE MATERIALS; AIRFRAMES; WINGS; DESIGN ANALYSIS; LOADS (FORCES); RELIABILITY
Additions to the NASA Aeronautics and Space Database as of 12/28/2011
20110023745 Akron Univ., Akron, OH, United States
An Experimental Investigation of Leak Rate Performance of a Subscale Candidate Elastomer Docking Space Seal
Garafolo, Nicholas G.; Daniels, Christopher C.; November 2011; In English; 46th Joint Propulsion Conference and Exhibit, 25-28 Jul. 2010, Nashville, TN, United States; Original contains color illustrations
Contract(s)/Grant(s): NNC08CA35CWBS 644423.06.31.04.01.03.22
Report No.(s): NASA/CR-2011-216829; AIAA Paper 2010-6907; E-17457; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023745
A novel docking seal was developed for the main interface seal of NASA s Low Impact Docking System (LIDS). This interface seal was designed to maintain acceptable leak rates while being exposed to the harsh environmental conditions of outer space. In this experimental evaluation, a candidate docking seal assembly called Engineering Development Unit (EDU58) was characterized and evaluated against the Constellation Project leak rate requirement. The EDU58 candidate seal assembly was manufactured from silicone elastomer S0383-70 vacuum molded in a metal retainer ring. Four seal designs were considered with unique characteristic heights. The leak rate performance was characterized through a mass point leak rate method by monitoring gas properties within an internal control volume. The leakage performance of the seals were described herein at representative docking temperatures of -50, +23, and +50 C for all four seal designs. Leak performance was also characterized at 100, 74, and 48 percent of full closure. For all conditions considered, the candidate seal assemblies met the Constellation Project leak rate requirement.
Author
DOCKING; LEAKAGE; ELASTOMERS; SILICONES; SEALS (STOPPERS)
20110023747 NASA Glenn Research Center, Cleveland, OH, United States
Development Status of PEM Non-Flow-Through Fuel Cell System Technology for NASA Applications
Hoberecht, Mark A.; Jakupca, Ian J.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 038957.04.06.01.03
Report No.(s): NASA/TM-2011-217107; E-17783; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023747
Today s widespread development of proton-exchange-membrane (PEM) fuel cell technology for commercial users owes its existence to NASA, where fuel cell technology saw its first applications. Beginning with the early Gemini and Apollo programs, and continuing to this day with the Shuttle Orbiter program, fuel cells have been a primary source of electrical power for many NASA missions. This is particularly true for manned missions, where astronauts are able to make use of the by-product of the fuel cell reaction, potable water. But fuel cells also offer advantages for unmanned missions, specifically when power requirements exceed several hundred watts and primary batteries are not a viable alternative. In recent years, NASA s Exploration Technology Development Program (ETDP) funded the development of fuel cell technology for applications that provide both primary power and regenerative fuel cell energy storage for planned Exploration missions that involved a return to the moon. Under this program, the Altair Lunar Lander was a mission requiring fuel cell primary power. There were also various Lunar Surface System applications requiring regenerative fuel cell energy storage, in which a fuel cell and electrolyzer combine to form an energy storage system with hydrogen, oxygen, and water as common reactants. Examples of these systems include habitat modules and large rovers. In FY11, the ETDP has been replaced by the Enabling Technology Development and Demonstration Program (ETDDP), with many of the same technology goals and requirements applied against NASA s revised Exploration portfolio.
Author
FUEL CELLS; ENERGY STORAGE; TECHNOLOGY UTILIZATION; REGENERATIVE FUEL CELLS; SPACE SHUTTLE ORBITERS; MEMBRANES; PROTONS
20110023748 NASA Glenn Research Center, Cleveland, OH, United States
The Effect of Boundary Support and Reflector Dimensions on Inflatable Parabolic Antenna Performance
Coleman, Michael J.; Baginski, Frank; Romanofsky, Robert R.; November 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNX07AR67G; NNX09AH08GWBS 439432,04,04,01
Report No.(s): NASA/TM-2011-217110; E-17786; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023748
For parabolic antennas with sufficient surface accuracy, more power can be radiated with a larger aperture size. This paper explores the performance of antennas of various size and reflector depth. The particular focus is on a large inflatable elastic antenna reflector that is supported about its perimeter by a set of elastic tendons and is subjected to a constant hydrostatic pressure. The surface accuracy of the antenna is measured by an RMS calculation, while the reflector phase error component of the efficiency is determined by computing the power density at boresight. In the analysis, the calculation of antenna efficiency is not based on the Ruze Equation. Hence, no assumption regarding the distribution of the reflector surface distortions is presumed. The reflector surface is modeled as an isotropic elastic membrane using a linear stress-strain constitutive relation. Three types of antenna reflector construction are considered: one molded to an ideal parabolic form and two different flat panel design patterns. The flat panel surfaces are constructed by seaming together panels in a manner that the desired parabolic shape is approximately attained after pressurization. Numerical solutions of the model problem are calculated under a variety of conditions in order to estimate the accuracy and efficiency of these antenna systems. In the case of the flat panel constructions, several different cutting patterns are analyzed in order to determine an optimal cutting strategy.
Author
MICROWAVE ANTENNAS; PARABOLIC ANTENNAS; ANTENNA DESIGN; LARGE SPACE STRUCTURES; MEMBRANE STRUCTURES; STRESS-STRAIN RELATIONSHIPS; STRUCTURAL DESIGN
20110023749 NASA Glenn Research Center, Cleveland, OH, United States
Initial Experiments of High-Speed Drive System Windage Losses
Handschuh, Robert F.; Hurrell, Michael J.; November 2011; In English; International Conference on Gears, 4-6 Oct. 2010, Garching, Germany; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.D7.03.01.01.01
Report No.(s): NASA/TM-2011-216925; E-17421-1; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023749
High speed gearing performance is very important to the overall drive system efficiency. Certain losses such as gear meshing and bearing drag can be minimized by design changes such as pressure angle of the gears and the geometry and type of bearings being used. One component that can have a large effect on the overall performance of high-speed drive systems is the parasitic drag known as gear windage. This loss mechanism is not well understood and minimizing this component is usually accomplished through much trial and error. The results presented in this paper will document some of the design parameter effects on the amount of windage losses. A new test facility at NASA Glenn has been assembled to systematically study the design variables. Results from recent tests will be presented. The tests are for a single gear, with and without lubricants, and some initial studies using shrouds.
Author
GEARS; HIGH SPEED; POWER TRANSMISSION; SYSTEM EFFECTIVENESS; DRAG; DESIGN ANALYSIS
20110023750 NASA Glenn Research Center, Cleveland, OH, United States
Data Analysis Techniques for a Lunar Surface Navigation System Testbed
Chelmins, David; Sands, O. Scott; Swank, Aaron; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 903184.04.20.03.02.01
Report No.(s): NASA/TM-2011-217113; E-17789; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023750
NASA is interested in finding new methods of surface navigation to allow astronauts to navigate on the lunar surface. In support of the Vision for Space Exploration, the NASA Glenn Research Center developed the Lunar Extra-Vehicular Activity Crewmember Location Determination System and performed testing at the Desert Research and Technology Studies event in 2009. A significant amount of sensor data was recorded during nine tests performed with six test subjects. This paper provides the procedure, formulas, and techniques for data analysis, as well as commentary on applications.
Author
LUNAR SURFACE; SURFACE NAVIGATION; SPACE EXPLORATION
20110023751 NASA Glenn Research Center, Cleveland, OH, United States
Advanced Gear Alloys for Ultra High Strength Applications
Shen, Tony; Krantz, Timothy; Sebastian, Jason; November 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217121; AHS 2011-000285; E-17810; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023751
Single tooth bending fatigue (STBF) test data of UHS Ferrium C61 and C64 alloys are presented in comparison with historical test data of conventional gear steels (9310 and Pyrowear 53) with comparable statistical analysis methods. Pitting and scoring tests of C61 and C64 are works in progress. Boeing statistical analysis of STBF test data for the four gear steels (C61, C64, 9310 and Pyrowear 53) indicates that the UHS grades exhibit increases in fatigue strength in the low cycle fatigue (LCF) regime. In the high cycle fatigue (HCF) regime, the UHS steels exhibit better mean fatigue strength endurance limit behavior (particularly as compared to Pyrowear 53). However, due to considerable scatter in the UHS test data, the anticipated overall benefits of the UHS grades in bending fatigue have not been fully demonstrated. Based on all the test data and on Boeing s analysis, C61 has been selected by Boeing as the gear steel for the final ERDS demonstrator test gearboxes. In terms of potential follow-up work, detailed physics-based, micromechanical analysis and modeling of the fatigue data would allow for a better understanding of the causes of the experimental scatter, and of the transition from high-stress LCF (surface-dominated) to low-stress HCF (subsurface-dominated) fatigue failure. Additional STBF test data and failure analysis work, particularly in the HCF regime and around the endurance limit stress, could allow for better statistical confidence and could reduce the observed effects of experimental test scatter. Finally, the need for further optimization of the residual compressive stress profiles of the UHS steels (resulting from carburization and peening) is noted, particularly for the case of the higher hardness C64 material.
Author
FATIGUE TESTS; STEELS; GEARS; BENDING FATIGUE; FAILURE ANALYSIS; RESIDUAL STRESS; MICROMECHANICS; TRANSMISSIONS (MACHINE ELEMENTS); COMPRESSION LOADS
20110023752 NASA Glenn Research Center, Cleveland, OH, United States
Thermal Energy for Lunar In Situ Resource Utilization: Technical Challenges and Technology Opportunities
Gordon, Pierce E. C.; Colozza, Anthony J.; Hepp, Aloysius F.; Heller, Richard S.; Gustafson, Robert; Stern, Ted; Nakamura, Takashi; October 2011; In English; 49th Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 4-7 Jan. 2011, Orlando, FL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 387498.01.04.01.07.01.03
Report No.(s): NASA/TM-2011-217114; AIAA Paper 2011-704; E-17801; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023752
Oxygen production from lunar raw materials is critical for sustaining a manned lunar base but is very power intensive. Solar concentrators are a well-developed technology for harnessing the Sun s energy to heat regolith to high temperatures (over 1375 K). The high temperature and potential material incompatibilities present numerous technical challenges. This study compares and contrasts different solar concentrator designs that have been developed, such as Cassegrains, offset parabolas, compound parabolic concentrators, and secondary concentrators. Differences between concentrators made from lenses and mirrors, and between rigid and flexible concentrators are also discussed. Possible substrate elements for a rigid mirror concentrator are selected and then compared, using the following (target) criteria: (low) coefficient of thermal expansion, (high) modulus of elasticity, and (low) density. Several potential lunar locations for solar concentrators are compared; environmental and processing-related challenges related to dust and optical surfaces are addressed. This brief technology survey examines various sources of thermal energy that can be utilized for materials processing on the lunar surface. These include heat from nuclear or electric sources and solar concentrators. Options for collecting and transporting thermal energy to processing reactors for each source are examined. Overall system requirements for each thermal source are compared and system limitations, such as maximum achievable temperature are discussed.
Author
THERMAL ENERGY; IN SITU RESOURCE UTILIZATION; REGOLITH; OXYGEN PRODUCTION; SOLAR COLLECTORS; LUNAR ROCKS; MODULUS OF ELASTICITY
20110023753 NASA Glenn Research Center, Cleveland, OH, United States
Investigation of Bearing Fatigue Damage Life Prediction Using Oil Debris Monitoring
Dempsey, Paula J.; Bolander, Nathan; Haynes, Chris; Toms, Allison M.; November 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217117; E-17804; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023753
Research was performed to determine if a diagnostic tool for detecting fatigue damage of helicopter tapered roller bearings can be used to determine remaining useful life (RUL). The taper roller bearings under study were installed on the tail gearbox (TGB) output shaft of UH- 60M helicopters, removed from the helicopters and subsequently installed in a bearing spall propagation test rig. The diagnostic tool was developed and evaluated experimentally by collecting oil debris data during spall progression tests on four bearings. During each test, data from an on-line, in-line, inductance type oil debris sensor was monitored and recorded for the occurrence of pitting damage. Results from the four bearings tested indicate that measuring the debris generated when a bearing outer race begins to spall can be used to indicate bearing damage progression and remaining bearing life.
Author
ROTARY WING AIRCRAFT; TRANSMISSIONS (MACHINE ELEMENTS); SHAFTS (MACHINE ELEMENTS); HELICOPTERS; FATIGUE (MATERIALS); ROLLER BEARINGS; LIFE (DURABILITY); DATA ACQUISITION
20110023754 NASA Glenn Research Center, Cleveland, OH, United States
Fiber Optic Strain Sensor for Planetary Gear Diagnostics
Kiddy, Jason S.; FROM; Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason; November 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217123; AHS 2011-000154; E-17812; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023754
This paper presents a new sensing approach for helicopter damage detection in the planetary stage of a helicopter transmission based on a fiber optic strain sensor array. Complete helicopter transmission damage detection has proven itself a difficult task due to the complex geometry of the planetary reduction stage. The crowded and complex nature of the gearbox interior does not allow for attachment of sensors within the rotating frame. Hence, traditional vibration-based diagnostics are instead based on measurements from externally mounted sensors, typically accelerometers, fixed to the gearbox exterior. However, this type of sensor is susceptible to a number of external disturbances that can corrupt the data, leading to false positives or missed detection of potentially catastrophic faults. Fiber optic strain sensors represent an appealing alternative to the accelerometer. Their small size and multiplexibility allows for potentially greater sensing resolution and accuracy, as well as redundancy, when employed as an array of sensors. The work presented in this paper is focused on the detection of gear damage in the planetary stage of a helicopter transmission using a fiber optic strain sensor band. The sensor band includes an array of 13 strain sensors, and is mounted on the ring gear of a Bell Helicopter OH-58C transmission. Data collected from the sensor array is compared to accelerometer data, and the damage detection results are presented
Author
DAMAGE; DETECTION; FIBER OPTICS; HELICOPTER PROPELLER DRIVE; HELICOPTERS; TRANSMISSIONS (MACHINE ELEMENTS); STRAIN GAGES; STRUCTURAL STRAIN
20110023755 NASA Glenn Research Center, Cleveland, OH, United States
SpaceWire Tiger Team Findings and Suggestions
Ishac, Joseph A.; November 2011; In English
Contract(s)/Grant(s): WBS 289972.10.03.03
Report No.(s): NASA/TM-2011-217201; E-17886; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023755
This technical report intends to highlight the key findings and recommendations of the SpaceWire Tiger Team for the CoNNeCT project. It covers findings which are technical in nature, covering design concepts and approaches.
Author
COMPUTER PROGRAMS; COMPUTERS; RADIO EQUIPMENT; AVIONICS
20110023756
Dynamic Testing of the NASA Hypersonic Project Combined Cycle Engine Testbed for Mode Transition Experiments
November 2011; In English; 58th JANNAF Joint Interagency Propulsion Committee Meeting, 18-22 Apr. 2011, Arlington, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 599489.02.07.03.05
Report No.(s): NASA/TM-2011-217133; E-17826; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023756
NASA is interested in developing technology that leads to more routine, safe, and affordable access to space. Access to space using airbreathing propulsion systems has potential to meet these objectives based on Airbreathing Access to Space (AAS) system studies. To this end, the NASA Fundamental Aeronautics Program (FAP) Hypersonic Project is conducting fundamental research on a Turbine Based Combined Cycle (TBCC) propulsion system. The TBCC being studied considers a dual flow-path inlet system. One flow-path includes variable geometry to regulate airflow to a turbine engine cycle. The turbine cycle provides propulsion from take-off to supersonic flight. The second flow-path supports a dual-mode scramjet (DMSJ) cycle which would be initiated at supersonic speed to further accelerate the vehicle to hypersonic speed. For a TBCC propulsion system to accelerate a vehicle from supersonic to hypersonic speed, a critical enabling technology is the ability to safely and effectively transition from the turbine to the DMSJ-referred to as mode transition. To experimentally test methods of mode transition, a Combined Cycle Engine (CCE) Large-scale Inlet testbed was designed with two flow paths-a low speed flow-path sized for a turbine cycle and a high speed flow-path designed for a DMSJ. This testbed system is identified as the CCE Large-Scale Inlet for Mode Transition studies (CCE-LIMX). The test plan for the CCE-LIMX in the NASA Glenn Research Center (GRC) 10- by 10-ft Supersonic Wind Tunnel (10x10 SWT) is segmented into multiple phases. The first phase is a matrix of inlet characterization (IC) tests to evaluate the inlet performance and establish the mode transition schedule. The second phase is a matrix of dynamic system identification (SysID) experiments designed to support closed-loop control development at mode transition schedule operating points for the CCE-LIMX. The third phase includes a direct demonstration of controlled mode transition using a closed loop control system developed with the data obtained from the first two phases. Plans for a fourth phase include mode transition experiments with a turbine engine. This paper, focusing on the first two phases of experiments, presents developed operational and analysis tools for streamlined testing and data reduction procedures.
Author
AIR FLOW; ENGINE INLETS; DYNAMIC TESTS; HYPERSONIC SPEED; PROPULSION SYSTEM CONFIGURATIONS; TURBINE ENGINES
20110023757 NASA Glenn Research Center, Cleveland, OH, United States
Computational Analysis of a Low-Boom Supersonic Inlet
Chima, Rodrick V.; November 2011; In English; 29th Applied Aerodynamics Conference, 27-30 Jun. 2011, Honolulu, HI, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.01,03,13,02
Report No.(s): NASA/TM-2011-217223; AIAA Paper 2011-3801; E-17906; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023757
A low-boom supersonic inlet was designed for use on a conceptual small supersonic aircraft that would cruise with an over-wing Mach number of 1.7. The inlet was designed to minimize external overpressures, and used a novel bypass duct to divert the highest shock losses around the engine. The Wind-US CFD code was used to predict the effects of capture ratio, struts, bypass design, and angles of attack on inlet performance. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center. Test results showed that the inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a stable operating range much larger than that of an engine. Predictions generally compared very well with the experimental data, and were used to help interpret some of the experimental results.
Author
COMPUTATIONAL FLUID DYNAMICS; ENGINE INLETS; SUPERSONIC AIRCRAFT; SUPERSONIC INLETS; INLET AIRFRAME CONFIGURATIONS; OVERPRESSURE; SUPERSONIC FLOW; SONIC BOOMS; WIND TUNNEL TESTS
20110023758 NASA Glenn Research Center, Cleveland, OH, United States
Computational Assessment of the Aerodynamic Performance of a Variable-Speed Power Turbine for Large Civil Tilt-Rotor Application
Welch, Gerard E.; November 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, Va, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.02.01
Report No.(s): NASA/TM-2011-217124; E-17813; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023758
The main rotors of the NASA Large Civil Tilt-Rotor notional vehicle operate over a wide speed-range, from 100% at take-off to 54% at cruise. The variable-speed power turbine offers one approach by which to effect this speed variation. Key aero-challenges include high work factors at cruise and wide (40 to 60 deg.) incidence variations in blade and vane rows over the speed range. The turbine design approach must optimize cruise efficiency and minimize off-design penalties at take-off. The accuracy of the off-design incidence loss model is therefore critical to the turbine design. In this effort, 3-D computational analyses are used to assess the variation of turbine efficiency with speed change. The conceptual design of a 4-stage variable-speed power turbine for the Large Civil Tilt-Rotor application is first established at the meanline level. The design of 2-D airfoil sections and resulting 3-D blade and vane rows is documented. Three-dimensional Reynolds Averaged Navier-Stokes computations are used to assess the design and off-design performance of an embedded 1.5-stage portion-Rotor 1, Stator 2, and Rotor 2-of the turbine. The 3-D computational results yield the same efficiency versus speed trends predicted by meanline analyses, supporting the design choice to execute the turbine design at the cruise operating speed.
Author
AERODYNAMIC CHARACTERISTICS; COMPUTATIONAL FLUID DYNAMICS; NAVIER-STOKES EQUATION; REYNOLDS AVERAGING; TILT ROTOR AIRCRAFT; TURBINES; ROTARY WINGS
20110023759 NASA Glenn Research Center, Cleveland, OH, United States
Planetary Gearbox Fault Detection Using Vibration Separation Techniques
Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason; November 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, VA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217127; AHS 2011-000134; E-17816; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023759
Studies were performed to demonstrate the capability to detect planetary gear and bearing faults in helicopter main-rotor transmissions. The work supported the Operations Support and Sustainment (OSST) program with the U.S. Army Aviation Applied Technology Directorate (AATD) and Bell Helicopter Textron. Vibration data from the OH-58C planetary system were collected on a healthy transmission as well as with various seeded-fault components. Planetary fault detection algorithms were used with the collected data to evaluate fault detection effectiveness. Planet gear tooth cracks and spalls were detectable using the vibration separation techniques. Sun gear tooth cracks were not discernibly detectable from the vibration separation process. Sun gear tooth spall defects were detectable. Ring gear tooth cracks were only clearly detectable by accelerometers located near the crack location or directly across from the crack. Enveloping provided an effective method for planet bearing inner- and outer-race spalling fault detection.
Author
CRACKS; FAULT DETECTION; GEAR TEETH; ROTARY WINGS; TRANSMISSIONS (MACHINE ELEMENTS); VIBRATION; BEARINGS
20110023760 NASA Langley Research Center, Hampton, VA, United States
Deployment of a Pressure Sensitive Paint System for Measuring Global Surface Pressures on Rotorcraft Blades in Simulated Forward Flight: Preliminary PSP Results from Test 581 in the 14- by 22-Foot Subsonic Tunnel
Watkins, Anthony Neal; Leighty, Bradley D.; Lipford, William E.; Wong, Oliver D.; Goodman, Kyle Z.; Crafton, James; Forlines, Alan; Goss, Larry; Gregory, James W.; Juliano, Thomas J.; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.07.06.03.01
Report No.(s): NASA/TM-2011-217316; L-20095; NF1676L-13838; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023760
This report will present details of a Pressure Sensitive Paint (PSP) system for measuring global surface pressures on the tips of rotorcraft blades in simulated forward flight at the 14- x 22-Foot Subsonic Tunnel. The system was designed to use a pulsed laser as an excitation source and PSP data was collected using the lifetime-based approach. With the higher intensity of the laser, this allowed PSP images to be acquired during a single laser pulse, resulting in the collection of crisp images that can be used to determine blade pressure at a specific instant in time. This is extremely important in rotorcraft applications as the blades experience dramatically different flow fields depending on their position in the rotor disk. Testing of the system was performed using the U.S. Army General Rotor Model System equipped with four identical blades. Two of the blades were instrumented with pressure transducers to allow for comparison of the results obtained from the PSP. This report will also detail possible improvements to the system.
Author
PRESSURE MEASUREMENT; PRESSURE SENSITIVE PAINTS; FLOW DISTRIBUTION; FLIGHT SIMULATION; PRESSURE SENSORS; HORIZONTAL FLIGHT; BLADE TIPS
20110023761 NASA Glenn Research Center, Cleveland, OH, United States
An Overview of NASA Engine Ice-Crystal Icing Research
Addy, Harold E., Jr.; Veres, Joseph P.; November 2011; In English; FROM International Conference on Aircraft and Engine Icing and Ground Deicing, 13-17 Jun. 2011, Chicago, IL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 648987.02.02.. 03.10
Report No.(s): NASA/TM-2011-217254; E-18009; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023761
Ice accretions that have formed inside gas turbine engines as a result of flight in clouds of high concentrations of ice crystals in the atmosphere have recently been identified as an aviation safety hazard. NASA s Aviation Safety Program (AvSP) has made plans to conduct research in this area to address the hazard. This paper gives an overview of NASA s engine ice-crystal icing research project plans. Included are the rationale, approach, and details of various aspects of NASA s research.
Author
AIRCRAFT SAFETY; ICE FORMATION; HAZARDS; FLIGHT SAFETY; ICE MAPPING
20110023762 NASA Glenn Research Center, Cleveland, OH, United States
Axisymmetric Calculations of a Low-Boom Inlet in a Supersonic Wind Tunnel
Chima, Rodrick V.; Hirt, Stefanie M.; Reger, Robert; November 2011; In English; 29th Applied Aerodynamics Conference, 27-30 Jun. 2011, Honolulu, HI, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.13.02
Report No.(s): NASA/TM-2011-217224; AIAA Paper 2011-3800; E-17907; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023762
This paper describes axisymmetric CFD predictions made of a supersonic low-boom inlet with a facility diffuser, cold pipe, and mass flow plug within wind tunnel walls, and compares the CFD calculations with the experimental data. The inlet was designed for use on a small supersonic aircraft that would cruise at Mach 1.6, with a Mach number over the wing of 1.7. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center in the fall of 2010 to demonstrate the performance and stability of a practical flight design that included a novel bypass duct. The inlet design is discussed here briefly. Prior to the test, CFD calculations were made to predict the performance of the inlet and its associated wind tunnel hardware, and to estimate flow areas needed to throttle the inlet. The calculations were done with the Wind-US CFD code and are described in detail. After the test, comparisons were made between computed and measured shock patterns, total pressure recoveries, and centerline pressures. The results showed that the dual-stream inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a large stable operating range. Predicted core recovery agreed well with the experiment but predicted bypass recovery and maximum capture ratio were high. Calculations of offdesign performance of the inlet along a flight profile agreed well with measurements and previous calculations.
Author
SUPERSONIC INLETS; COMPUTATIONAL FLUID DYNAMICS; MASS FLOW; FLIGHT PATHS; SUPERSONIC AIRCRAFT; STABILITY
20110023763 Boeing Co., Canoga Park, CA, United States
Power Management and Distribution (PMAD) Model Development: Final Report
Metcalf, Kenneth J.; November 2011; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NAS3-01140WBS 432938.08
Report No.(s): NASA/CR-2011-217268; E-18023; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023763
Power management and distribution (PMAD) models were developed in the early 1990's to model candidate architectures for various Space Exploration Initiative (SEI) missions. They were used to generate "ballpark" component mass estimates to support conceptual PMAD system design studies. The initial set of models was provided to NASA Lewis Research Center (since renamed Glenn Research Center) in 1992. They were developed to estimate the characteristics of power conditioning components predicted to be available in the 2005 timeframe. Early 90's component and device designs and material technologies were projected forward to the 2005 timeframe, and algorithms reflecting those design and material improvements were incorporated into the models to generate mass, volume, and efficiency estimates for circa 2005 components. The models are about ten years old now and NASA GRC requested a review of them to determine if they should be updated to bring them into agreement with current performance projections or to incorporate unforeseen design or technology advances. This report documents the results of this review and the updated power conditioning models and new transmission line models generated to estimate post 2005 PMAD system masses and sizes. This effort continues the expansion and enhancement of a library of PMAD models developed to allow system designers to assess future power system architectures and distribution techniques quickly and consistently.
Author
PERFORMANCE PREDICTION; POWER CONDITIONING; MATHEMATICAL MODELS; WEIGHT (MASS); ELECTRIC EQUIPMENT; FREQUENCY CONVERTERS; CIRCUITS; ELECTRIC POWER TRANSMISSION
20110023766 NASA Ames Research Center, Moffett Field, CA, United States
On Multiple-Layered Vortices
Rossow, Vernon J.; June 2011; In English; Original contains black and white illustrations
Report No.(s): NASA/TM-2011-216424; ARC-E-DAA-TN2797; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023766
As part of an ongoing effort to find ways to make vortex flow fields decompose more quickly, photographs and observations are presented of vortex flow fields that indicate the presence of multiple layers of fluid rotating about a common axis. A survey of the literature indicates that multiple-layered vortices form in waterspouts, tornadoes and lift-generated vortices of aircraft. An explanation for the appearance of multiple-layered structures in vortices is suggested. The observations and data presented are intended to improve the understanding of the formation and persistence of vortex flow fields.
Author
FLOW DISTRIBUTION; VORTICES; LAYERS; ROTATING LIQUIDS; DROPS (LIQUIDS); VERTICAL AIR CURRENTS
20110023767 NASA Ames Research Center, Moffett Field, CA, United States
Investigating the Nature of and Methods for Managing Metroplex Operations
Atkins, Stephen; Capozzi, Brian; Hinkey, Jim; Idris, Husni; Kaiser, Kent; June 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNA07BC56CWBS 305295.02.07.01.05.08
Report No.(s): NASA/CR-2011-216413; ARC-E-DAA-TN2292; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023767
A combination of traffic demand growth, Next Generation Air Transportation System (NextGen) technologies and operational concepts, and increased utilization of regional airports is expected to increase the occurrence and severity of coupling between operations at proximate airports. These metroplex phenomena constrain the efficiency and/or capacity of airport operations and, in NextGen, have the potential to reduce safety and prevent environmental benefits. Without understanding the nature of metroplexes and developing solutions that provide efficient coordination of operations between closely-spaced airports, the use of NextGen technologies and distribution of demand to regional airports may provide little increase in the overall metroplex capacity. However, the characteristics and control of metroplex operations have not received significant study. This project advanced the state of knowledge about metroplexes by completing three objectives: 1. developed a foundational understand of the nature of metroplexes; 2. provided a framework for discussing metroplexes; 3. suggested and studied an approach for optimally managing metroplexes that is consistent with other NextGen concepts
Derived from text
AIR TRANSPORTATION; AIRPORTS; COORDINATION; AIR TRAFFIC CONTROL; AIR TRAFFIC; FLIGHT SAFETY; MODELS
Additions to the NASA Aeronautics and Space Database as of 12/29/2011
20110023803 NASA Ames Research Center, Moffett Field, CA, United States
High-Temperature Modal Survey of a Hot-Structure Control Surface
Spivey, Natalie D.; June 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-215965; DFRC-1034; DFRC-E-DAA-TN2764; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023803
Ground vibration tests are routinely conducted for supporting flutter analysis for subsonic and supersonic vehicles; however, for hypersonic vehicles, thermoelastic vibration testing techniques are neither well established nor routinely performed. New high-temperature material systems, fabrication technologies and high-temperature sensors expand the opportunities to develop advanced techniques for performing ground vibration tests at elevated temperatures. When high-temperature materials, which increase in stiffness when heated, are incorporated into a hot-structure that contains metallic components that decrease in stiffness when heated, the interaction between those materials can affect the hypersonic flutter analysis. A high-temperature modal survey will expand the research database for hypersonics and improve the understanding of this dual-material interaction. This report discusses the vibration testing of the carbon-silicon carbide Ruddervator Subcomponent Test Article, which is a truncated version of a full-scale hot-structure control surface. Two series of room-temperature modal test configurations were performed in order to define the modal characteristics of the test article during the elevated-temperature modal survey: one with the test article suspended from a bungee cord (free-free) and the second with it mounted on the strongback (fixed boundary). Testing was performed in the NASA Dryden Flight Research Center Flight Loads Laboratory Large Nitrogen Test Chamber.
Author
CONTROL SURFACES; HIGH TEMPERATURE; WIND TUNNEL TESTS; FABRICATION; VIBRATION TESTS; CARBON-SILICON CARBIDE COMPOSITES; X-37 VEHICLE
20110023839 NASA Langley Research Center, Hampton, VA, United States
Doppler Radar Profiler for Launch Winds at the Kennedy Space Center (Phase 1a)
Murri, Daniel G.; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 869021.05.01.06.03
Report No.(s): NASA/TM-2011-217321; NESC-RP-11-00692; L-20107; NF1676L-13979; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023839
The NASA Engineering and Safety Center (NESC) received a request from the, NASA Technical Fellow for Flight Mechanics at Langley Research Center (LaRC), to develop a database from multiple Doppler radar wind profiler (DRWP) sources and develop data processing algorithms to construct high temporal resolution DRWP wind profiles for day-of-launch (DOL) vehicle assessment. This document contains the outcome of Phase 1a of the assessment including Findings, Observations, NESC Recommendations, and Lessons Learned.
Author
DOPPLER RADAR; WIND PROFILES; LAUNCH VEHICLES; METEOROLOGICAL RADAR; WIND (METEOROLOGY); FLIGHT MECHANICS
20110023847 NASA Dryden Flight Research Center, Edwards, CA, United States
Data Driven Model Development for the SuperSonic SemiSpan Transport (S(sup 4)T)
Kukreja, Sunil L.; March 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.02.20.03.01
Report No.(s): NASA/TM-2011-215966; DFRC-E-DAA-TN2767; H-3076; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023847
In this report, we will investigate two common approaches to model development for robust control synthesis in the aerospace community; namely, reduced order aeroservoelastic modelling based on structural finite-element and computational fluid dynamics based aerodynamic models, and a data-driven system identification procedure. It is shown via analysis of experimental SuperSonic SemiSpan Transport (S4T) wind-tunnel data that by using a system identification approach it is possible to estimate a model at a fixed Mach, which is parsimonious and robust across varying dynamic pressures.
Author
AERODYNAMIC CHARACTERISTICS; AEROSERVOELASTICITY; COMPUTATIONAL FLUID DYNAMICS; FINITE ELEMENT METHOD; DYNAMIC PRESSURE; DYNAMIC STRUCTURAL ANALYSIS; DATA SYSTEMS; DYNAMIC RESPONSE
Additions to the NASA Aeronautics and Space Database as of 12/30/2011
20110023913 NASA Dryden Flight Research Center, Edwards, CA, United States
Unsteady Aerodynamic Model Tuning for Precise Flutter Prediction
Pak, Chan-gi; April 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-215963; H-3088; DFRC-E-DAA-TN2778; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110023913
A simple method for an unsteady aerodynamic model tuning is proposed in this study. This method is based on the direct modification of the aerodynamic influence coefficient matrices. The aerostructures test wing 2 flight-test data is used to demonstrate the proposed model tuning method. The flutter speed margin computed using only the test validated structural dynamic model can be improved using the additional unsteady aerodynamic model tuning, and then the flutter speed margin requirement of 15 percent in military specifications can apply towards the test validated aeroelastic model. In this study, unsteady aerodynamic model tunings are performed at two time invariant flight conditions, at Mach numbers of 0.390 and 0.456. When the Mach number for the unsteady aerodynamic model tuning approaches to the measured fluttering Mach number, 0.502, at the flight altitude of 9,837 ft, the estimated flutter speed is approached to the measured flutter speed at this altitude. The minimum flutter speed difference between the estimated and measured flutter speed is -0.14 percent.
Author
AERODYNAMIC COEFFICIENTS; AERODYNAMIC CHARACTERISTICS; AEROELASTICITY; FLIGHT TESTS; FLUTTER ANALYSIS; INFLUENCE COEFFICIENT; PREDICTION ANALYSIS TECHNIQUES; UNSTEADY AERODYNAMICS
Additions to the NASA Aeronautics and Space Database as of 01/03/2012
20110024032 NASA Dryden Flight Research Center, Edwards, CA, United States
Basis Function Approximation of Transonic Aerodynamic Influence Coefficient Matrix
Li, Wesley W.; Pak, Chan-gi; March 2011; In English; Original contains black and white illustrations
Report No.(s): NASA/TM-2011-216423; H-3082; DFRC-E-DAA-TN2479; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110024032
A technique for approximating the modal aerodynamic influence coefficients matrices by using basis functions has been developed and validated. An application of the resulting approximated modal aerodynamic influence coefficients matrix for a flutter analysis in transonic speed regime has been demonstrated. This methodology can be applied to the unsteady subsonic, transonic, and supersonic aerodynamics. The method requires the unsteady aerodynamics in frequency-domain. The flutter solution can be found by the classic methods, such as rational function approximation, k, p-k, p, root-locus et cetera. The unsteady aeroelastic analysis for design optimization using unsteady transonic aerodynamic approximation is being demonstrated using the ZAERO flutter solver (ZONA Technology Incorporated, Scottsdale, Arizona). The technique presented has been shown to offer consistent flutter speed prediction on an aerostructures test wing 2 configuration with negligible loss in precision in transonic speed regime. These results may have practical significance in the analysis of aircraft aeroelastic calculation and could lead to a more efficient design optimization cycle.
Author
AERODYNAMIC COEFFICIENTS; APPROXIMATION; DESIGN OPTIMIZATION; FLUTTER ANALYSIS; INFLUENCE COEFFICIENT; MATRICES (MATHEMATICS); PREDICTION ANALYSIS TECHNIQUES; TRANSONIC FLOW; UNSTEADY AERODYNAMICS
Additions to the NASA Aeronautics and Space Database as of 01/06/2012
20110024205 NASA Marshall Space Flight Center, Huntsville, AL, United States
A Damage Tolerance Comparison of Composite Hat-Stiffened and Honeycomb Sandwich Structure for Launch Vehicle Interstage Applications
Nettles, A. T.; December 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-216477; M-1326; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20110024205
In this study, a direct comparison of the compression-after-impact (CAI) strength of impact-damaged, hat-stiffened and honeycomb sandwich structure for launch vehicle use was made. The specimens used consisted of small substructure designed to carry a line load of approx..3,000 lb/in. Damage was inflicted upon the specimens via drop weight impact. Infrared thermography was used to examine the extent of planar damage in the specimens. The specimens were prepared for compression testing to obtain residual compression strength versus damage severity curves. Results show that when weight of the structure is factored in, both types of structure had about the same CAI strength for a given damage level. The main difference was that the hat-stiffened specimens exhibited a multiphase failure whereas the honeycomb sandwich structure failed catastrophically.
Author
COMPRESSIVE STRENGTH; IMPACT STRENGTH; HONEYCOMB STRUCTURES; LAUNCH VEHICLES; DAMAGE; TOLERANCES (MECHANICS); RESIDUAL STRENGTH
Additions to the NASA Aeronautics and Space Database as of 01/17/2012
20120000031 NASA Langley Research Center, Hampton, VA, United States
A Concept for Flexible Operations and Optimized Traffic into Metroplex Regions
DeLaurentis, Daniel; Landry, Steve; Sun, Dengfeng; Wieland, Fred; Tyagi, Ankit; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NNL10AA15CWBS 305295.02.07.07.02
Report No.(s): NASA/CR-2011-217302; NF1676L-13770; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000031
A "Flexible Flight Operations" concept for airport metroplexes was studied. A flexible flight is one whose destination airport is not assigned until a threshold is reached near the arrival area at which time the runway which reduces overall delay is assigned. The concept seeks to increase throughput by exploiting flexibility. The quantification of best-case benefits from the concept was pursued to establish whether concept research is warranted. Findings indicate that indeed the concept has potential for significant reductions in delay (and cost due to delay) in the N90 (NY/NJ) and SCT (Southern California) metroplexes. Delay reductions of nearly 26% are possible in N90 when 30% of the commercial airline flights are flexible (smartly selected by their low probability of connecting passengers); nearly 40% delay reduction is found when 50% of the flights are flexible. In the SCT metroplex, delay reductions estimates are greater. Greater reductions result at SCT since it is less constrained currently than N90, providing "more room" to take advantage of flexibility. Using the flexible operations concept for on-demand/air taxi and General Aviation flights were found to be beneficial at NY/NJ, indicating the flexible operations concepts may be useful to wide variety of users..
Author
FLEXIBILITY; PROBABILITY THEORY; AIRPORTS; COMMERCIAL AIRCRAFT; ESTIMATES; GENERAL AVIATION AIRCRAFT; CIVIL AVIATION
20120000033 NASA, Washington, DC, United States
NASA Risk Management Handbook Version 1.0
Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher; Maggio, Gaspare; Stamatelatos, Michael; Youngblood, Robert; Guarro, Sergio; Rutledge, Peter; Sherrard, James; Smith, Curtis; Williams, Rodney; November 2011; In English; Original contains color illustrations
Report No.(s): NASA/SP-2011-3422-Version-1.0; HQ-STI-11-205; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000033
The purpose of this handbook is to provide guidance for implementing the Risk Management (RM) requirements of NASA Procedural Requirements (NPR) document NPR 8000.4A, Agency Risk Management Procedural Requirements [1], with a specific focus on programs and projects, and applying to each level of the NASA organizational hierarchy as requirements flow down. This handbook supports RM application within the NASA systems engineering process, and is a complement to the guidance contained in NASA/SP-2007-6105, NASA Systems Engineering Handbook [2]. Specifically, this handbook provides guidance that is applicable to the common technical processes of Technical Risk Management and Decision Analysis established by NPR 7123.1A, NASA Systems Engineering Process and Requirements [3]. These processes are part of the \Systems Engineering Engine. (Figure 1) that is used to drive the development of the system and associated work products to satisfy stakeholder expectations in all mission execution domains, including safety, technical, cost, and schedule. Like NPR 7123.1A, NPR 8000.4A is a discipline-oriented NPR that intersects with product-oriented NPRs such as NPR 7120.5D, NASA Space Flight Program and Project Management Requirements [4]; NPR 7120.7, NASA Information Technology and Institutional Infrastructure Program and Project Management Requirements [5]; and NPR 7120.8, NASA Research and Technology Program and Project Management Requirements [6]. In much the same way that the NASA Systems Engineering Handbook is intended to provide guidance on the implementation of NPR 7123.1A, this handbook is intended to provide guidance on the implementation of NPR 8000.4A. 1.2 Scope and Depth This handbook provides guidance for conducting RM in the context of NASA program and project life cycles, which produce derived requirements in accordance with existing systems engineering practices that flow down through the NASA organizational hierarchy. The guidance in this handbook is not meant to be prescriptive. Instead, it is meant to be general enough, and contain a sufficient diversity of examples, to enable the reader to adapt the methods as needed to the particular risk management issues that he or she faces. The handbook highlights major issues to consider when managing programs and projects in the presence of potentially significant uncertainty, so that the user is better able to recognize and avoid pitfalls that might otherwise be experienced.
Author
RISK MANAGEMENT; MANAGEMENT ANALYSIS; SYSTEMS ENGINEERING; HANDBOOKS; DECISION THEORY; INFORMATION SYSTEMS; SCHEDULES; PROJECT MANAGEMENT; NASA SPACE PROGRAMS
20120000056 NASA Glenn Research Center, Cleveland, OH, United States
Investigation of the Mechanical Performance of Compliant Thermal Barriers
DeMange, Jeffrey J.; Bott, Robert J.; Dunlap, Patrick H.; December 2011; In English; 17th International Space Planes and Hypersonic Systems and Technologies Conference, 11-14 Apr. 2011, San Francisco, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC08CA35CWBS 644423.06.31.03.08.03
Report No.(s): NASA/TM-2011-217142; AIAA Paper-2011-2388; E-17879; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000056
Compliant thermal barriers play a pivotal role in the thermal protection systems of advanced aerospace vehicles. Both the thermal properties and mechanical performance of these barriers are critical in determining their successful implementation. Due to the custom nature of many thermal barriers, designers of advanced spacecraft have little guidance as to the design, selection, and implementation of these elements. As part of an effort to develop a more fundamental understanding of the interrelationship between thermal barrier design and performance, mechanical testing of thermal barriers was conducted. Two different types of thermal barriers with several core insulation density levels ranging from 62 to 141 kg/cu m were investigated. Room-temperature compression tests were conducted on samples to determine load performance and assess thermal barrier resiliency. Results showed that the loading behavior of these thermal barriers was similar to other porous, low-density, compliant materials, such as elastomeric foams. Additionally, the insulation density level had a significant non-linear impact on the stiffness and peak loads of the thermal barriers. In contrast, neither the thermal barrier type nor the level of insulation density significantly influenced the room-temperature resiliency of the samples.
Author
THERMAL PROTECTION; LOW DENSITY MATERIALS; COMPRESSION TESTS; ELASTIC PROPERTIES; LOADS (FORCES); PERFORMANCE TESTS; THERMODYNAMIC PROPERTIES
20120000057 NASA Glenn Research Center, Cleveland, OH, United States
Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation
Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo; November 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217106; E-17681-1; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000057
An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.
Author
GEARS; GREASES; LUBRICANTS; LOADS (FORCES); HEAT TRANSFER; FRICTION FACTOR; FAILURE; LUBRICATION; HIGH TEMPERATURE
20120000061 NASA Glenn Research Center, Cleveland, OH, United States
The Dust Management Project: Final Report
Hyatt, Mark J.; Straka, Sharon; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 936374.01.03
Report No.(s): NASA/TM-2011-217037; E-17743; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000061
A return to the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth s economic sphere, will require investment in developing new technologies and capabilities to achieve affordable and sustainable human exploration. From the operational experience gained and lessons learned during the Apollo missions, conducting longterm operations in the lunar environment will be a particular challenge, given the difficulties presented by the unique physical properties and other characteristics of lunar regolith, including dust. The Apollo missions and other lunar explorations have identified significant lunar dust-related problems that will challenge future mission success. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it s potentially harmful effects on exploration systems and human explorers. The Dust Management Project (DMP) is tasked with the evaluation of lunar dust effects, assessment of the resulting risks, and development of mitigation and management strategies and technologies related to Exploration Systems architectures. To this end, the DMP supports the overall goal of the Exploration Technology Development Program (ETDP) of addressing the relevant high priority technology needs of multiple elements within the Constellation Program (CxP) and sister ETDP projects. Project scope, approach, accomplishments, summary of deliverables, and lessons learned are presented.
Author
LUNAR DUST; CONSTELLATION PROGRAM; GRAVITATIONAL EFFECTS; MAN ENVIRONMENT INTERACTIONS; MARS MISSIONS; PERTURBATION; REGOLITH; LUNAR EXPLORATION
20120000062 NASA Glenn Research Center, Cleveland, OH, United States
Implementation of a Sage-Based Stirling Model Into a System-Level Numerical Model of the Fission Power System Technology Demonstration Unit
Briggs, Maxwell H.; December 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 463169.04.03.01.02
Report No.(s): NASA/TM-2011-217203; NETS-2011-3271; E-17603; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000062
The Fission Power System (FPS) project is developing a Technology Demonstration Unit (TDU) to verify the performance and functionality of a subscale version of the FPS reference concept in a relevant environment, and to verify component and system models. As hardware is developed for the TDU, component and system models must be refined to include the details of specific component designs. This paper describes the development of a Sage-based pseudo-steady-state Stirling convertor model and its implementation into a system-level model of the TDU.
Author
FISSION; STIRLING CYCLE; MATHEMATICAL MODELS
20120000064 NASA Glenn Research Center, Cleveland, OH, United States
Evaluation of Surface Modification as a Lunar Dust Mitigation Strategy for Thermal Control Surfaces
Gaier, James R.; Waters, Deborah L.; Misconin, Robert M.; Banks, Bruce A.; Crowder, Mark; December 2011; In English; 41st International Conference on Environmental Systems, 17-21 Jul. 2011, Portland, OR, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 119103.04.05.18
Report No.(s): NASA/TM-2011-217230; AIAA Paper-2011-5183; E-17817-1; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000064
Three surface treatments were evaluated for their ability to lower the adhesion between lunar simulant dust and AZ93, AlFEP, and AgFEP thermal control surfaces under simulated lunar conditions. Samples were dusted in situ and exposed to a standardized puff of nitrogen gas. Thermal performance before dusting, after dusting, and after part of the dust was removed by the puff of gas, were compared to perform the assessment. None of the surface treatments was found to significantly affect the adhesion of lunar simulants to AZ93 thermal control paint. Oxygen ion beam texturing also did not lower the adhesion of lunar simulant dust to AlFEP or AgFEP. But a workfunction matching coating and a proprietary Ball Aerospace surface treatment were both found to significantly lower the adhesion of lunar simulants to AlFEP and AgFEP. Based on these results, it is recommended that all these two techniques be further explored as dust mitigation coatings for AlFEP and AgFEP thermal control surfaces.
Author
TEMPERATURE CONTROL; LUNAR DUST; CONTROL SURFACES; TEMPERATURE EFFECTS; SURFACE TREATMENT; ADHESION; DUST COLLECTORS
20120000065 NASA Glenn Research Center, Cleveland, OH, United States
Post-Test Analysis of a 10-Year Sodium Heat Pipe Life Test
Rosenfeld, John H.; Locci, Ivan E.; Sanzi, James L.; Hull, David R.; Geng, Steven M.; December 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): NAS3-26925WBS 463169.04.03,01.02
Report No.(s): NASA/TM-2011-217206; NETS-2011-3619; E-17627; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000065
High-temperature heat pipes are being evaluated for use in energy conversion applications such as fuel cells, gas turbine re-combustors, Stirling cycle heat sources; and with the resurgence of space nuclear power both as reactor heat removal elements and as radiator elements. Long operating life and reliable performance are critical requirements for these applications. Accordingly, long-term materials compatibility is being evaluated through the use of high-temperature life test heat pipes. Thermacore, Inc., has carried out a sodium heat pipe 10-year life test to establish long-term operating reliability. Sodium heat pipes have demonstrated favorable materials compatibility and heat transport characteristics at high operating temperatures in air over long time periods. A representative one-tenth segment Stirling Space Power Converter heat pipe with an Inconel 718 envelope and a stainless steel screen wick has operated for over 87,000 hr (10 years) at nearly 700 C. These life test results have demonstrated the potential for high-temperature heat pipes to serve as reliable energy conversion system components for power applications that require long operating lifetime with high reliability. Detailed design specifications, operating history, and post-test analysis of the heat pipe and sodium working fluid are described. Lessons learned and future life test plans are also discussed.
Author
HEAT PIPES; STIRLING CYCLE; SERVICE LIFE; HIGH TEMPERATURE TESTS; SODIUM; HEAT TRANSFER; DESIGN ANALYSIS; ENERGY CONVERSION
20120000068 NASA Glenn Research Center, Cleveland, OH, United States
Concept Design of High Power Solar Electric Propulsion Vehicles for Human Exploration
Hoffman, David J.; Kerslake, Thomas W.; Hojnicki, Jeffrey S.; Manzella, David H.; Falck, Robert D.; Cikanek, Harry A., III; Klem, Mark D.; Free, James M.; December 2011; In English; 62nd International Astronautical Congress, 3-7 Oct. 2011, Cape Town, South Africa; Original contains color illustrations
Contract(s)/Grant(s): WBS 432938.08.01.03.01
Report No.(s): NASA/TM-2011-217281; IAC-11-D2.3.5; E-18036; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000068
Human exploration beyond low Earth orbit will require enabling capabilities that are efficient, affordable and reliable. Solar electric propulsion (SEP) has been proposed by NASA s Human Exploration Framework Team as one option to achieve human exploration missions beyond Earth orbit because of its favorable mass efficiency compared to traditional chemical propulsion systems. This paper describes the unique challenges associated with developing a large-scale high-power (300-kWe class) SEP vehicle and design concepts that have potential to meet those challenges. An assessment of factors at the subsystem level that must be considered in developing an SEP vehicle for future exploration missions is presented. Overall concepts, design tradeoffs and pathways to achieve development readiness are discussed.
Author
SOLAR ELECTRIC PROPULSION; PROPULSION SYSTEM CONFIGURATIONS; PROPULSION SYSTEM PERFORMANCE; CHEMICAL PROPULSION; SPACE EXPLORATION; LOW EARTH ORBITS
20120000069 NASA Glenn Research Center, Cleveland, OH, United States
Thermal Optical Properties of Lunar Dust Simulants and Their Constituents
Gaier, James R.; Ellis, Shaneise; Hanks, Nichole; December 2011; In English; 3rd Atmospheric and Space Environments Conference, 27-30 Jun. 2011, Honolulu, HI, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS WBS 119103.04.05.18
Report No.(s): NASA/TM-2011-217232; AIAA Paper 2011-3673; E-17807-1; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000069
The total reflectance spectra of lunar simulant dusts (< 20 mm particles) were measured in order to determine their integrated solar absorptance (alpha) and their thermal emittance (epsilon) for the purpose of analyzing the effect of dust on the performance of thermal control surfaces. All of the simulants except one had a wavelength-dependent reflectivity (p (lambda)) near 0.10 over the wavelength range of 8 to 25 microns and so are highly emitting at room temperature and lower. The 300 K emittance (epsilon) of all the lunar simulants except one ranged from 0.78 to 0.92. The exception was Minnesota Lunar Simulant 1 (MLS-1), which has little or no glassy component. In all cases the epsilon was lower for the < 20 micron particles than for larger particles reported earlier. There was considerably more variation in the lunar simulant reflectance in the solar spectral range (250 to 2500 nm) than in the thermal infrared. As expected, the lunar highlands simulants were more reflective in this wavelength range than the lunar mare simulants. The integrated solar absorptance (alpha) of the simulants ranged from 0.39 to 0.75. This is lower than values reported earlier for larger particles of the same simulants (0.41 to 0.82), and for representative mare and highlands lunar soils (0.74 to 0.91). Since the of some mare simulants more closely matched that of highlands lunar soils, it is recommended that and values be the criteria for choosing a simulant for assessing the effects of dust on thermal control surfaces, rather than whether a simulant has been formulated as a highlands or a mare simulant.
Author
TEMPERATURE CONTROL; LUNAR DUST; LUNAR SOIL; DUST COLLECTORS; CONTROL SURFACES; REFLECTANCE; THERMAL EMISSION; THERMODYNAMIC PROPERTIES
20120000070 NASA Glenn Research Center, Cleveland, OH, United States
Evaluation of Brushing as a Lunar Dust Mitigation Strategy for Thermal Control Surfaces
Gaier, James R.; Journey, Khrissaundra; Christopher, Steven; Davis, Shanon; December 2011; In English; 41st International Conference on Environmental Systems, 17-21 Jul. 2011, Portland, OR, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 119103.04.05.18
Report No.(s): NASA/TM-2011-217231; AIAA Paper-2011-5182; E-17806-1; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000070
Evaluation of brushing to remove lunar simulant dust from thermal control surfaces is described. First, strip brushes made with nylon, PTFE, or Thunderon (Nihon Sanmo Dyeing Company Ltd.) bristles were used to remove JSC-1AF dust from AZ93 thermal control paint or aluminized FEP (AlFEP) thermal control surface under ambient laboratory conditions. Nylon and PTFE bristles removed a promising amount of dust from AZ93, and nylon and Thunderon bristles from AlFEP. But when these were tested under simulated lunar conditions in the lunar dust adhesion bell jar (LDAB), they were not effective. In a third effort, seven brushes made up of three different materials, two different geometries, and different bristle lengths and thicknesses were tested under laboratory conditions against AZ93 and AlFEP. Two of these brushes, the Zephyr fiberglass fingerprint brush and the Escoda nylon fan brush, removed over 90 percent of the dust, and so were tested in the fourth effort in the LDAB. They also performed well under these conditions recovering 80 percent or more of the original thermal performance (solar absorptance/thermal emittance) of both AZ93 and AgFEP after 20 strokes, and 90 or more percent after 200 strokes
Author
LUNAR DUST; CONTROL SURFACES; DUST COLLECTORS; TEMPERATURE CONTROL; THERMAL EMISSION; SOLAR ENERGY ABSORBERS; SURFACE PROPERTIES; GLASS FIBERS; TEMPERATURE EFFECTS; BRUSHES
Additions to the NASA Aeronautics and Space Database as of 01/20/2012
20120000497 NASA Dryden Flight Research Center, Edwards, CA, United States
Fairing Well: Aerodynamic Truck Research at NASA Dryden Flight Research Center
Gelzer, Christian; 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NND08RR01B
Report No.(s): NASA/SP-2010-4545; DFRC-E-DAA-TN2315; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000497
In 1973 engineers at Dryden began investigating ways to reduce aerodynamic drag on land vehicles. They began with a delivery van whose shape they changed dramatically, finally reducing its aerodynamic drag by more than 5 percent. They then turned their attention to tracator-trailers, modifying a cab-over and reducing its aerodynamic drag by nearly 25 percent. Further research identified additional areas worth attention, but in the intervening decades few of those changes have appeared.
Author
AERODYNAMIC DRAG; AERODYNAMICS; DRAG REDUCTION; SHAPES; TRAILERS; TRUCKS
Additions to the NASA Aeronautics and Space Database as of 01/23/2012
20120000504 NASA Langley Research Center, Hampton, VA, United States
Constitutive Soil Properties for Mason Sand and Kennedy Space Center
Thomas, Michael A.; Chitty, Daniel E.; December 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNL07AA00BWBS 747797.06.13.06.31.04.40
Report No.(s): NASA/CR-2011-217323; NF1676L-13996; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000504
Accurate soil models are required for numerical simulations of land landings for the Orion Crew Exploration Vehicle (CEV). This report provides constitutive material models for two soil conditions at Kennedy Space Center (KSC) and four conditions of Mason Sand. The Mason Sand is the test sand for LaRC s drop tests and swing tests of the Orion. The soil models are based on mechanical and compressive behavior observed during geotechnical laboratory testing of remolded soil samples. The test specimens were reconstituted to measured in situ density and moisture content. Tests included: triaxial compression, hydrostatic compression, and uniaxial strain. A fit to the triaxial test results defines the strength envelope. Hydrostatic and uniaxial tests define the compressibility. The constitutive properties are presented in the format of LSDYNA Material Model 5: Soil and Foam. However, the laboratory test data provided can be used to construct other material models. The soil models are intended to be specific to the soil conditions they were tested at. The two KSC models represent two conditions at KSC: low density dry sand and high density in-situ moisture sand. The Mason Sand model was tested at four conditions which encompass measured conditions at LaRC s drop test site.
Author
SOIL SAMPLING; CREW EXPLORATION VEHICLE; MATHEMATICAL MODELS; SANDS; MECHANICAL PROPERTIES; SPACECRAFT LANDING; GEOTECHNICAL ENGINEERING
Additions to the NASA Aeronautics and Space Database as of 01/27/2012
20120000701 NASA Johnson Space Center, Houston, TX, United States
Investigating the Relationship Between Personality Traits and Astronaut Career Performance: Retrospective Analysis of Personality Data Collected 1989-1995
Mussib, David; Keeton, Kathryn E.; December 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-217353; S-1115; Copyright; Distribution under U.S. Government purpose rights; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000701
This report presents an analysis of an existing astronaut psychological trait dataset and the relationship between those data and publicly available metrics of astronaut career performance. The overall aim of this analysis is to examine the relationship between individual factors (i.e., predictors), identifiable at the time of selection, and career activity (i.e., performance) as an astronaut. Sections include: outcome variables (quantifying career performance); analysis of the data (the personality data set, analytic strategy, and demographic factors and astronaut career performance); trait predictors and performance; a summary of the analysis; and suggestions for next steps.This project is funded by a contractual agreement between the author and the Behavioral Health and Performance Research Element at EASI/Wyle and NASA. This work was undertaken for the purpose of informing future selection strategies for astronaut applicants, and to create a better understanding of the relationship between individual psychological characteristics and the job of being an astronaut
Author
ASTRONAUT PERFORMANCE; PERSONNEL SELECTION; PERSONALITY; PSYCHOLOGICAL FACTORS; PREDICTIONS; PERSONALITY TESTS; SPACE PSYCHOLOGY
Additions to the NASA Aeronautics and Space Database as of 01/31/2012
20120000734 NASA Langley Research Center, Hampton, VA, United States
Examination of Relationship Between Photonic Signatures and Fracture Strength of Fused Silica Used in Orbiter Windows
Yost, William T.; Cramer, K. Elliott; Estes, Linda R.; Salem, Jonathan A.; Lankford, James, Jr.; Lesniak, Jon; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 604746.02.22.07.01.01.04
Report No.(s): NASA/TP-2011-217322; L-20101; NF1676L-13924; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000734
A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outermost pane of the orbiter windows. Four categories of damage: hyper-velocity impacts that occur during space-flight (HVI); hypervelocity impacts artificially made at the Hypervelocity Impact Technology Facility (HIT-F); impacts made by larger objects falling onto the pane surface to simulate dropped items on the window during service/storage of vehicle (Bruises); and light scratches from dull objects designed to mimic those that might occur by dragging a dull object across the glass surface (Chatter Checks) are examined. The damage sites are cored from fused silica window carcasses, examined with the GFP and other methodologies, and broken using the ASTM Standard C1499-09 to measure the fracture strength. A correlation is made between the fracture strength and damage-site measurements including geometrical measurements and GFP measurements of photoelastic retardation (stress patterns) surrounding the damage sites. An analytical damage model to predict fracture strength from photoelastic retardation measurements is presented and compared with experimental results.
Author
FRACTURE STRENGTH; HYPERVELOCITY IMPACT; IMPACT DAMAGE; POLARISCOPES; SILICA GLASS; AEROSPACE VEHICLES; WINDOWS (APERTURES); PHOTONICS; MATHEMATICAL MODELS
Additions to the NASA Aeronautics and Space Database as of 02/02/2012
20120000789 NASA Glenn Research Center, Cleveland, OH, United States
A Small Fission Power System for NASA Planetary Science Missions
Mason, Lee; Casani, John; Elliott, John; Fleurial, Jean-Pierre; MacPherson, Duncan; Nesmith, William; Houts, Michael; Bechtel, Ryan; Werner, James; Kapernick, Rick; Poston, David; Qualls, Arthur Lou; Lipinski, Ron; Radel, Ross; Bailey, Sterling; Weitzberg, Abraham; December 2011; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 463169.04.03.01.02
Report No.(s): NASA/TM-2011-217099; NETS-2011-3318; E-17606; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000789
In March 2010, the Decadal Survey Giant Planets Panel (GPP) requested a short-turnaround study to evaluate the feasibility of a small Fission Power System (FPS) for future unspecified National Aeronautics and Space Administration (NASA) science missions. FPS technology was considered a potential option for power levels that might not be achievable with radioisotope power systems. A study plan was generated and a joint NASA and Department of Energy (DOE) study team was formed. The team developed a set of notional requirements that included 1-kW electrical output, 15-year design life, and 2020 launch availability. After completing a short round of concept screening studies, the team selected a single concept for concentrated study and analysis. The selected concept is a solid block uranium-molybdenum reactor core with heat pipe cooling and distributed thermoelectric power converters directly coupled to aluminum radiator fins. This paper presents the preliminary configuration, mass summary, and proposed development program.
Author
FISSION; THERMOELECTRIC GENERATORS; POWER CONVERTERS; REACTOR CORES; GAS GIANT PLANETS
20120000791 NASA Dryden Flight Research Center, Edwards, CA, United States
Horizontal Launch: A Versatile Concept for Assured Space Access
Bartolotta, Paul; Wilhite, Alan W.; Schaffer, Mark; Voland, Randall T.; Huebner, Larry; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): NCC1-02043; NNX11CB64CWBS 599489.02.07.02.14.01
Report No.(s): NASA/SP-2011-215994; DFRC-E-DAA-TN4418; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000791
The vision of horizontal launch is the capability to provide a mobile launch pad that can use existing aircraft runways, cruise above weather, loiter for mission instructions, and achieve precise placement for orbital intercept, rendezvous, or reconnaissance. Another compelling benefit of horizontal launch is that today s ground-based vertical launch pads are a single earthquake, hurricane, or terrorist attack away from disruption of critical U.S. launch capabilities. The study did not attempt to design a new system concept for horizontal launch, but rather focused on the refinement of many previously-studied horizontal launch concepts. Because of the large number of past horizontal launch studies, a process was developed to narrow the number of concepts through prescreening, screening, and evaluation of point designs. The refinement process was not intended to select the "best" concept, but rather to establish the feasibility of horizontal launch from a balanced assessment of figures of merit and to identify potential concepts that warrant further exploration.
Author
LAUNCHING; ORBITAL RENDEZVOUS; PROPULSION SYSTEM CONFIGURATIONS; PAYLOADS; PROPULSION SYSTEM PERFORMANCE; MARKET RESEARCH
Additions to the NASA Aeronautics and Space Database as of 02/06/2012
20120000866 NASA Glenn Research Center, Cleveland, OH, United States
Design and Test Plans for a Non-Nuclear Fission Power System Technology Demonstration Unit
Mason, Lee; Palac, Donald; Gibson, Marc; Houts, Michael; Warren, John; Werner, James; Poston, David; Qualls, Arthur Lou; Radel, Ross; Harlow, Scott; December 2012; In English; Nuclear and Emerging Technologies for Space (NETS-2011), 7-10 Feb. 2011, Albuquerque, NM, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 429698.01.03
Report No.(s): NASA/TM-2011-217100; NETS-2011-3327; E-17608; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000866
A joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) team is developing concepts and technologies for affordable nuclear Fission Power Systems (FPSs) to support future exploration missions. A key deliverable is the Technology Demonstration Unit (TDU). The TDU will assemble the major elements of a notional FPS with a non-nuclear reactor simulator (Rx Sim) and demonstrate system-level performance in thermal vacuum. The Rx Sim includes an electrical resistance heat source and a liquid metal heat transport loop that simulates the reactor thermal interface and expected dynamic response. A power conversion unit (PCU) generates electric power utilizing the liquid metal heat source and rejects waste heat to a heat rejection system (HRS). The HRS includes a pumped water heat removal loop coupled to radiator panels suspended in the thermal-vacuum facility. The basic test plan is to subject the system to realistic operating conditions and gather data to evaluate performance sensitivity, control stability, and response characteristics. Upon completion of the testing, the technology is expected to satisfy the requirements for Technology Readiness Level 6 (System Demonstration in an Operational and Relevant Environment) based on the use of high-fidelity hardware and prototypic software tested under realistic conditions and correlated with analytical predictions.
Author
NUCLEAR REACTORS; ELECTRICAL RESISTANCE; HEAT SOURCES; CONTROL STABILITY; DYNAMIC RESPONSE; HEAT TRANSFER; NUCLEAR FISSION
20120000867 NASA Glenn Research Center, Cleveland, OH, United States
Helical Face Gear Development Under the Enhanced Rotorcraft Drive System Program
Heath, Gregory F.; Slaughter, Stephen C.; Fisher, David J.; Lewicki, David G.; Fetty, Jason; December 2011; In English; 67th Annual Forum and Technology Display (Forum 67), 3-5 May 2011, Virginia Beach, VA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.01
Report No.(s): NASA/TM-2011-217125; AHS 2011-000270; E-17814; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000867
U.S. Army goals for the Enhanced Rotorcraft Drive System Program are to achieve a 40 percent increase in horsepower to weight ratio, a 15 dB reduction in drive system generated noise, 30 percent reduction in drive system operating, support, and acquisition cost, and 75 percent automatic detection of critical mechanical component failures. Boeing s technology transition goals are that the operational endurance level of the helical face gearing and related split-torque designs be validated to a TRL 6, and that analytical and manufacturing tools be validated. Helical face gear technology is being developed in this project to augment, and transition into, a Boeing AH-64 Block III split-torque face gear main transmission stage, to yield increased power density and reduced noise. To date, helical face gear grinding development on Northstar s new face gear grinding machine and pattern-development tests at the NASA Glenn/U.S. Army Research Laboratory have been completed and are described.
Author
AH-64 HELICOPTER; ROTARY WING AIRCRAFT; NOISE REDUCTION; GEARS; GRINDING MACHINES; FAILURE
20120000908 NASA Glenn Research Center, Cleveland, OH, United States
Comparison of In-Situ, Model and Ground Based In-Flight Icing Severity
Johnston, Christopher J.; Serke, David J.; Adriaansen, Daniel R.; Reehorst, Andrew L.; Politovich, Marica K.; Wolff, Cory A.; McDonough, Frank; December 2011; In English; 15th Symposium on Integrated Observing and Assimilation Systems for the Atmosphere, Oceans, and Land Surface (IOAS-AOLS), 27 Jan. 2011, Seattle, WA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 648987.02.04.03.10
Report No.(s): NASA/TM-2011-217141; Paper No. 10.2; E-17878; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000908
As an aircraft flies through supercooled liquid water, the liquid freezes instantaneously to the airframe thus altering its lift, drag, and weight characteristics. In-flight icing is a contributing factor to many aviation accidents, and the reliable detection of this hazard is a fundamental concern to aviation safety. The scientific community has recently developed products to provide in-flight icing warnings. NASA's Icing Remote Sensing System (NIRSS) deploys a vertically--pointing Ka--band radar, a laser ceilometer, and a profiling multi-channel microwave radiometer for the diagnosis of terminal area in-flight icing hazards with high spatial and temporal resolution. NCAR s Current Icing Product (CIP) combines several meteorological inputs to produce a gridded, three-dimensional depiction of icing severity on an hourly basis. Pilot reports are the best and only source of information on in-situ icing conditions encountered by an aircraft. The goal of this analysis was to ascertain how the testbed NIRSS icing severity product and the operational CIP severity product compare to pilot reports of icing severity, and how NIRSS and CIP compare to each other. This study revealed that the icing severity product from the ground-based NASA testbed system compared very favorably with the operational model-based product and pilot reported in-situ icing.
Author
FLIGHT SAFETY; AIRCRAFT SAFETY; REMOTE SENSING; AIRCRAFT ICING; CLOUD HEIGHT INDICATORS
20120000909 NASA Glenn Research Center, Cleveland, OH, United States
Efficient Design and Analysis of Lightweight Reinforced Core Sandwich and PRSEUS Structures
Bednarcyk, Brett A.; Yarrington, Phillip W.; Lucking, Ryan C.; Collier, Craig S.; Ainsworth, James J.; December 2012; In English; 52nd Structures, Structural Dynamics, and Materials Conference, 4-7 Apr. 2011, Demver, CO, Oman; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 944244,04,02,03
Report No.(s): NASA/TM-2011-217198; AIAA Paper 2011-1909; E-17883; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000909
Design, analysis, and sizing methods for two novel structural panel concepts have been developed and incorporated into the HyperSizer Structural Sizing Software. Reinforced Core Sandwich (RCS) panels consist of a foam core with reinforcing composite webs connecting composite facesheets. Boeing s Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panels use a pultruded unidirectional composite rod to provide axial stiffness along with integrated transverse frames and stitching. Both of these structural concepts are ovencured and have shown great promise applications in lightweight structures, but have suffered from the lack of efficient sizing capabilities similar to those that exist for honeycomb sandwich, foam sandwich, hat stiffened, and other, more traditional concepts. Now, with accurate design methods for RCS and PRSEUS panels available in HyperSizer, these concepts can be traded and used in designs as is done with the more traditional structural concepts. The methods developed to enable sizing of RCS and PRSEUS are outlined, as are results showing the validity and utility of the methods. Applications include several large NASA heavy lift launch vehicle structures.
Author
SANDWICH STRUCTURES; HONEYCOMB STRUCTURES; COMPOSITE MATERIALS; STIFFNESS; DESIGN ANALYSIS; PANELS
20120000910 NASA Glenn Research Center, Cleveland, OH, United States
Solar Electric Propulsion (SEP) Tug Power System Considerations
Kerslake, Thomas W.; Bury, Kristen M.; Hojinicki, Jeffrey S.; Sajdak, Adam M.; Scheiddegger, Robert J.; December 2011; In English; 2011 Space Power Workshop, 18-21 Aprl. 2011, Los Angeles, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 735785.01.02.01.03
Report No.(s): NASA/TM-2011-217197; E-17882; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000910
Solar electric propulsion (SEP) technology is truly at the "intersection of commercial and military space" as well as the intersection of NASA robotic and human space missions. Building on the use of SEP for geosynchronous spacecraft station keeping, there are numerous potential commercial and military mission applications for SEP stages operating in Earth orbit. At NASA, there is a resurgence of interest in robotic SEP missions for Earth orbit raising applications, 1-AU class heliocentric missions to near Earth objects (NEOs) and SEP spacecraft technology demonstrations. Beyond these nearer term robotic missions, potential future human space flight missions to NEOs with high-power SEP stages are being considered. To enhance or enable this broad class of commercial, military and NASA missions, advancements in the power level and performance of SEP technologies are needed. This presentation will focus on design considerations for the solar photovoltaic array (PVA) and electric power system (EPS) vital to the design and operation of an SEP stage. The engineering and programmatic pros and cons of various PVA and EPS technologies and architectures will be discussed in the context of operating voltage and power levels. The impacts of PVA and EPS design options on the remaining SEP stage subsystem designs, as well as spacecraft operations, will also be discussed.
Author
ELECTRIC POTENTIAL; SOLAR ELECTRIC PROPULSION; SOLAR ARRAYS; STATIONKEEPING; GEOSYNCHRONOUS ORBITS; ROBOTICS; PHOTOVOLTAIC CELLS; NEAR EARTH OBJECTS
20120000911 NASA Glenn Research Center, Cleveland, OH, United States
Sol-Gel Synthesis of La(0.6)Sr(0.4)CoO(3-x) and Sm(0.5)Sr(0.5)CoO(3-x) Cathode Nanopowders for Solid Oxide Fuel Cells
Bansal, Narottam P.; Wise, Brent; December 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.14
Report No.(s): NASA/TM-2011-217222; E-17905; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000911
Nanopowders of La(0.6)Sr(0.4)CoO(3-x) (LSC) and Sm(0.5)Sr(0.5)CoO(3-x) (SSC) compositions, which are being investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC) with La(Sr)Ga(Mg)O(3-x) (LSGM) as the electrolyte, were synthesized by low-temperature sol-gel method using metal nitrates and citric acid. Thermal decomposition of the citrate gels was followed by simultaneous DSC/TGA methods. Development of phases in the gels, on heat treatments at various temperatures, was monitored by x-ray diffraction. Solgel powders calcined at 550 to 1000 C consisted of a number of phases. Single perovskite phase La(0.6)Sr(0.4)CoO(3-x) or Sm(0.5)Sr(0.5)CoO(3-x) powders were obtained at 1200 and 1300 C, respectively. Morphological analysis of the powders calcined at various temperatures was done by scanning electron microscopy. The average particle size of the powders was approx.15 nm after 700 C calcinations and slowly increased to 70 to 100 nm after heat treatments at 1300 to 1400 C.
Author
CATHODIC COATINGS; ELECTROLYTES; SOLID OXIDE FUEL CELLS; POWDER (PARTICLES); SCANNING ELECTRON MICROSCOPY; THERMAL DECOMPOSITION; THERMOGRAVIMETRY; HEAT TREATMENT
20120000912 NASA Glenn Research Center, Cleveland, OH, United States
Space Telecommunications Radio System (STRS) Compliance Testing
Handler, Louis M.; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS WBS 439432.04.07.01
Report No.(s): NASA/TM-2011-217266; STRS-ATP-00001; E-18021; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000912
The Space Telecommunications Radio System (STRS) defines an open architecture for software defined radios. This document describes the testing methodology to aid in determining the degree of compliance to the STRS architecture. Non-compliances are reported to the software and hardware developers as well as the NASA project manager so that any non-compliances may be fixed or waivers issued. Since the software developers may be divided into those that provide the operating environment including the operating system and STRS infrastructure (OE) and those that supply the waveform applications, the tests are divided accordingly. The static tests are also divided by the availability of an automated tool that determines whether the source code and configuration files contain the appropriate items. Thus, there are six separate step-by-step test procedures described as well as the corresponding requirements that they test. The six types of STRS compliance tests are: STRS application automated testing, STRS infrastructure automated testing, STRS infrastructure testing by compiling WFCCN with the infrastructure, STRS configuration file testing, STRS application manual code testing, and STRS infrastructure manual code testing. Examples of the input and output of the scripts are shown in the appendices as well as more specific information about what to configure and test in WFCCN for non-compliance. In addition, each STRS requirement is listed and the type of testing briefly described. Attached is also a set of guidelines on what to look for in addition to the requirements to aid in the document review process.
Author
TELECOMMUNICATION; COMPUTER PROGRAMS; SOFTWARE ENGINEERING; RADIO EQUIPMENT; STATIC TESTS; ARCHITECTURE (COMPUTERS)
20120000913 NASA Glenn Research Center, Cleveland, OH, United States
Buckling and Vibration of Fiber Reinforced Composite Plates With Nanofiber Reinforced Matrices
Chamis, Christos C.; Murthy, Pappu L. N.; December 2011; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561,581,02,08.03,13.05
Report No.(s): NASA/TM-2011-217282; E-18037; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000913
Anisotropic composite plates were evaluated with nanofiber reinforced matrices (NFRM). The nanofiber reinforcement volumes ratio in the matrix was 0.01. The plate dimensions were 20 by 10 by 1.0 in. (508 by 254 by 25.4 mm). Seven different loading condition cases were evaluated for buckling: three for uniaxial loading, three for pairs of combined loading, and one with three combined loadings. The anisotropy arose from the unidirectional plates having been at 30 from the structural axis. The anisotropy had a full 6 by 6 rigidities matrix which were satisfied and solved by a Galerkin buckling algorithm. For vibration the same conditions were used with the applied cods about a small fraction of the buckling loads. The buckling and vibration results showed that the NFRM plates buckled at about twice those with conventional matrix.
Author
ANISOTROPIC PLATES; REINFORCED PLATES; GALERKIN METHOD; BUCKLING; FIBER COMPOSITES; VIBRATION; ALGORITHMS
20120000914 NASA Glenn Research Center, Cleveland, OH, United States
Numerical Implementation of a Multiple-ISV Thermodynamically-Based Work Potential Theory for Modeling Progressive Damage and Failure in Fiber-Reinforced Laminates
Pineda, Evan J.; Waas, Anthony M.; December 2011; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 001098.04.02.03
Report No.(s): NASA/TM-2011-217401; E-18048; Copyright; Distribution as joint owner in the copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120000914
A thermodynamically-based work potential theory for modeling progressive damage and failure in fiber-reinforced laminates is presented. The current, multiple-internal state variable (ISV) formulation, enhanced Schapery theory (EST), utilizes separate ISVs for modeling the effects of damage and failure. Damage is considered to be the effect of any structural changes in a material that manifest as pre-peak non-linearity in the stress versus strain response. Conversely, failure is taken to be the effect of the evolution of any mechanisms that results in post-peak strain softening. It is assumed that matrix microdamage is the dominant damage mechanism in continuous fiber-reinforced polymer matrix laminates, and its evolution is controlled with a single ISV. Three additional ISVs are introduced to account for failure due to mode I transverse cracking, mode II transverse cracking, and mode I axial failure. Typically, failure evolution (i.e., post-peak strain softening) results in pathologically mesh dependent solutions within a finite element method (FEM) setting. Therefore, consistent character element lengths are introduced into the formulation of the evolution of the three failure ISVs. Using the stationarity of the total work potential with respect to each ISV, a set of thermodynamically consistent evolution equations for the ISVs is derived. The theory is implemented into commercial FEM software. Objectivity of total energy dissipated during the failure process, with regards to refinements in the FEM mesh, is demonstrated. The model is also verified against experimental results from two laminated, T800/3900-2 panels containing a central notch and different fiber-orientation stacking sequences. Global load versus displacement, global load versus local strain gage data, and macroscopic failure paths obtained from the models are compared to the experiments.
Author
FIBER COMPOSITES; PLASTIC DEFORMATION; COMPUTATIONAL GRIDS; DAMAGE; FIBER ORIENTATION; FINITE ELEMENT METHOD; LAMINATES
Additions to the NASA Aeronautics and Space Database as of 02/09/2012
20120001328 NASA Marshall Space Flight Center, Huntsville, AL, United States
Ares I Scale Model Acoustic Test Overpressure Results
Casiano, M. J.; Alvord, D. A.; McDaniels, D. M.; December 2011; In English; Original contains color illustrations
Report No.(s): NASA/TM-2011-217452; M-1328; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120001328
A summary of the overpressure environment from the 5% Ares I Scale Model Acoustic Test (ASMAT) and the implications to the full-scale Ares I are presented in this Technical Memorandum. These include the scaled environment that would be used for assessing the full-scale Ares I configuration, observations, and team recommendations. The ignition transient is first characterized and described, the overpressure suppression system configuration is then examined, and the final environment characteristics are detailed. The recommendation for Ares I is to keep the space shuttle heritage ignition overpressure (IOP) suppression system (below-deck IOP water in the launch mount and mobile launcher and also the crest water on the main flame deflector) and the water bags.
Author
OVERPRESSURE; SCALE MODELS; ARES 1 LAUNCH VEHICLE; SPACE TRANSPORTATION SYSTEM; COMPUTATIONAL FLUID DYNAMICS; IGNITION; ACOUSTICS
20120001338 NASA Langley Research Center, Hampton, VA, United States
Awareness and Detection of Traffic and Obstacles Using Synthetic and Enhanced Vision Systems
Bailey, Randall E.; January 2012; In English; Original contains color illustrations
Report No.(s): NASA/TM-2012-217324; L-20100; NF1676L-12443; No Copyright; Availability: CASI
Avail Online: http://hdl.handle.net/2060/20120001338
Research literature are reviewed and summarized to evaluate the awareness and detection of traffic and obstacles when using Synthetic Vision Systems (SVS) and Enhanced Vision Systems (EVS). The study identifies the critical issues influencing the time required, accuracy, and pilot workload associated with recognizing and reacting to potential collisions or conflicts with other aircraft, vehicles and obstructions during approach, landing, and surface operations. This work considers the effect of head-down display and head-up display implementations of SVS and EVS as well as the influence of single and dual pilot operations. The influences and strategies of adding traffic information and cockpit alerting with SVS and EVS were also included. Based on this review, a knowledge gap assessment was made with recommendations for ground and flight testing to fill these gaps and hence, promote the safe and effective implementation of SVS/EVS technologies for the Next Generation Air Transportation System
Author
ENHANCED VISION; GROUND TESTS; WORKLOADS (PSYCHOPHYSIOLOGY); FLIGHT TESTS; COCKPITS; AIR TRANSPORTATION
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