SCAN_02-01

02-01 AERODYNAMICS CHARACTERISTICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

02-02 AERODYNAMICS OF BODIES
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

02-03 AIRFOIL AND WING AERODYNAMICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

03-02 HELICOPTERS AND GROUND EFFECT MACHINES
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Advances in Modeling and Simulation of Rotorcraft Noise and Associated Impacts on Survivability
Document ID:
20090037593
Report #:
AD-A505765
Available Online:
http://hdl.handle.net/100.2/ADA505765
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Newman, Daniel (Defense Advanced Research Projects Agency) Doligalski, Thomas (Army Research Office) Minniti, Robert (Arion Systems, Inc.)
Journal:
Proceedings of the 26th Army Science Conference
Published:
20081201
Source:
Defense Advanced Research Projects Agency (Arlington, VA United States)
Pages:
9
Contract #:
None
Abstract:
The acoustic signature of a rotorcraft is often the primary means of detection and identification by enemy forces in the modern battlespace. Additionally, this detection is often accomplished without the need for the sophisticated sensing equipment required for other signature components. While this vulnerability has existed for many generations of rotorcraft, the tools for predicting the acoustic signature and understanding its impact on mission survivability have lagged in development. This is partially due the need for development of multidisciplinary knowledge and capability to predict the aerodynamic performance, structural dynamic response, near-field acoustic character, far-field atmospheric propagation and human perception as well as the historical lack of required computational resources. The advent of cheaper and more ubiquitous computational resources at the all levels in the rotorcraft community alleviated the later issue and left the need for a significant investment to address the former. Approximately four years ago, DARPA made this investment and identified teams of researchers guided by an advisory panel made up of industry and government experts aimed at developing the required assets. The DARPA funded Helicopter Quieting Program was initiated to focus on developing a suite of tools appropriate for use by the designer to predict the acoustic signature of rotorcraft. In the last year, the focus was expanded to leverage the signature prediction capabilities and develop tools appropriate for the mission planner and warfighter that enable visual analysis of the impact of signature change on survivability and operational effectiveness. The end product of this effort was three tool suites, verified using experimental data, capable of predicting the aerodynamic performance and acoustic signature of modern main rotors and the tools necessary to show the impact of signature changes on the mission effectiveness of the vehicle.
Language:
English
Notes:
Presented at the Army Science Conference (26th) held in Orlando, Florida on 1-4 December 2008. Published in the Proceedings of the Army Science Conference (26th), December 2008. The original document contains color images 26th Army Science Conference Orlando, FL 1-4 Dec. 2008

03-03 STOL AND VTOL AIRCRAFT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Pressurized Structure Technology for UAVS
Document ID:
20090037598
Report #:
AD-A505728
Available Online:
http://hdl.handle.net/100.2/ADA505728
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Edge, H. (Army Research Lab.) Nixon, M. (Army Research Lab.) Janas, A. (Army Research Lab.) Ross, W. (Army Research Lab.) Collins, J. (Army Research Lab.)
Journal:
Proceedings of the 26th Army Science Conference
Published:
20081201
Source:
Army Research Lab. (Aberdeen Proving Ground, MD United States)
Pages:
10
Contract #:
None
Abstract:
There is a critical need to improve the performance and utility of unmanned aerial vehicles (UAVs). Several areas of UAV performance need to be improved for the next generation of UAVS to be used successfully in expanded future combat roles. For example current time aloft is only on the order of an hour or two for electric-powered UAVs. The current generation of UAVs lacks vertical takeoff and landing (VTOL) capability and precision slow-speed maneuverability required for urban navigation and targeting. In addition, the UAVs are not capable of stealth, and are easily spotted and/or heard. These deficiencies are related mostly to the airframe and method of propulsion. Most fielded UAVs are currently based on fixed-wing or rotor-craft airframes and thus are constrained to their flight characteristics. UAV propulsion using ducted fans may also be fielded. In general, these vehicles require the motors, electrical or internal combustion to be running at high speed to keep the UAV aloft. This requires a substantial amount of energy and generates noise at excessive levels. One way to address the deficiencies of the UAVs just listed is to employ lighter-than-air or pressurized structure-based (PSB) technology. Basically, the UAV will be built such that a considerable percentage of its weight is supported by or constructed from inflatable structures containing air or helium. PSB technology will reduce the amount of energy required to keep the UAV aloft thus allowing the use of smaller, slower, and quieter motors. An airframe near neutral buoyancy will allow much slower flight speeds and increased maneuverability while expending little power. PSB airframes used in conjunction with technologies such as solar cells may be able to stay aloft for extended periods of time.
Language:
English
Notes:
Presented at the Army Science Conference (26th) in Orlando, FL on 1-4 Dec 2008 and published in proceedings of the same. See also ADM002187. The original document contains color images 26th Army Science Conference Orlando, FL 1-4 Dec. 2008

03-05 AIRCRAFT NOISE AND SONIC BOOM
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

03-06 AIRCRAFT SAFETY AND SAFETY DEVICES
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

03-07 CLEAR AIR TURBULENCE
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Dimits Shift in More Realistic Gyrokinetic Plasma Turbulence Simulations
Document ID:
20090037493
Report #:
DE2009-953703, PPPL-4336
Sales Agency:
National Technical Information Service (NTIS) No Copyright
Author(s):
Mikkelsen, D. R. Dorland, W.
Published:
20080701
Source:
Princeton Univ. (NJ United States)
Pages:
14
Contract #:
DE-AC02-76CH03073
Abstract:
In simulations of turbulent plasma transport due to long wavelength, (k/pi = 1), electrostatic drift-type instabilities we find that a nonlinear upshift of the effective threshold persists. This 'Dimits shift' represents the difference between the linear threshold, at the onset of instability, and the nonlinear threshold, where transport increases suddenly as the driving temperature gradient is increased. As the drive increases, the magnitudes of turbulent eddies and zonal ows grow until the zonal flows become nonlinearly unstable to 'tertiary' modes and their sheared ows no longer grow fast enough to strongly limit eddy size. The tertiary mode threshold sets the effective nonlinear threshold for the heat transport, and the Dimits shift arises when this occurs at a zonal flow magnitude greater than that needed to limit transport near the linear threshold. Next generation tokamaks will likely benefit from the higher effective threshold for turbulent transport, and transport models should incorporate suitable corrections to linear thresholds. These gyrokinetic simulations are more realistic than previous reports of a Dimits shift because they include nonadiabatic electron dynamics, strong collisional damping of zonal flows, and finite electron and ion collisionality together with realistic shaped magnetic geometry. Reversing previously reported results based on idealized adiabatic electrons, we find that increasing collisionality reduces the heat flux because collisionality reduces the nonadiabatic electron drive.
Language:
English
Notes:
Sponsored by Department of Energy, Washington, DC.

05-01 HYDRAULIC AND PNEUMATIC SYSTEMS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

05-02 AUXILIARY ELECTRICAL SYSTEMS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

07-01 JET PROPULSION
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

09-01 WIND TUNNELS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
A High-Order Transport Scheme for Collisional-Radiative and Nonequilibrium Plasma
Document ID:
20090037510
Report #:
AD-A505555, AFRL-RZ-ED-TP-2009-028
Available Online:
http://hdl.handle.net/100.2/ADA505555
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Kapper, Michael G. (Ohio State Univ.)
Published:
20090206
Source:
Ohio State Univ. (Columbus, OH United States) Texas Research Inst., Inc. (Austin, TX, United States)
Pages:
214
Contract #:
None
Abstract:
A series of shock tube experiments performed in the 1970s at the Institute for Aerospace Studies, University of Toronto, led in the discovery of instabilities in relaxing shock structures in noble gases under hypervelocity conditions. The instabilities were oscillatory in nature and found to affect the entire shock structure including the translational front, induction zone, and electron avalanche. Theoretical models were first developed in order to reproduce the length and time scales of the observed quasi-equilibrium state, and later extended to include unsteady plasma-dynamic simulations that verified the influence of pressure oscillations in one dimension. Despite these attempts, a complete explanation for the oscillations nor a quantitative analysis of the multi-dimensional shock structure has been provided to date. This dissertation builds upon previous modeling efforts, extending the numerical simulations to a high level of accuracy and detail so that coupling of complex wave phenomena and nonequilibrium effects can be well resolved. This has necessitated the development of a numerical capability aimed at relaxing shock layers and other unsteady, high-enthalpy nonequilibrium plasmas and is the focus of much of this work. The plasma is described as a two-temperature, single fluid with the electronic states convected as separate species. Solution of the convective transport is handled via upwind shock-capturing techniques, extended to third-order on general curvilinear meshes.
Language:
English
Notes:
Sponsored in part by Air Force Office of Scientific Research (AFOSR) laboratory task no. 02PR05COR

Title:
An Overview of the NASA FAP Hypersonics Project Airbreathing Propulsion Research
Document ID:
20090037583
Report #:
LF99-9121
Available Online:
http://hdl.handle.net/2060/20090037583
Sales Agency:
CASI Hardcopy A02 No Copyright
Author(s):
Auslender, A. H. (NASA Langley Research Center) Suder, Kenneth L. (NASA Glenn Research Center) Thomas, Scott R. (NASA Glenn Research Center)
Published:
20091019
Source:
NASA Glenn Research Center (Cleveland, OH, United States)
Pages:
7
Contract #:
None
Abstract:
The propulsion research portfolio of the National Aeronautics and Space Administration Fundamental Aeronautics Program Hypersonics Project encompasses a significant number of technical tasks that are aligned to achieve mastery and intellectual stewardship of the core competencies in the hypersonic-flight regime. An overall coordinated programmatic and technical effort has been structured to advance the state-of-the-art, via both experimental and analytical efforts. A subset of the entire hypersonics propulsion research portfolio is presented in this overview paper. To this end, two programmatic research disciplines are discussed; namely, (1) the Propulsion Discipline, including three associated research elements: the X-51A partnership, the HIFiRE-2 partnership, and the Durable Combustor Rig, and (2) the Turbine-Based Combine Cycle Discipline, including three associated research elements: the Combined Cycle Engine Large Scale Inlet Mode Transition Experiment, the small-scale Inlet Mode Transition Experiment, and the High-Mach Fan Rig.
Language:
English
Notes:
16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference Bremen 19-23 Oct. 2009