Simulation Software
NASA is one of the pioneering organizations advancing the
art of computational mechanics, which involves creation of mathematical
models of a product design and testing various configurations
by computer simulation before settling on a final design. Initially
used by NASA to model designs of flight vehicles, the technique
has expanded enormously over the last two decades to embrace
calculation and visual imagery of forces and phenomena that cannot
be simulated in conventional facilities, such as wind tunnels.
Its use has similarly grown from air and space applications to
cover a great variety of non-aerospace products from autos to
rollercoasters to medical equipment.
Workers at a Texaco oil field drill a vertical oil well. Texaco's
oil production is aided by a computational simulation code called
UNISIM.
These advances have been made possible by a great wealth of
software developed by government agencies and private companies.
The Small Business Innovation Research (SBIR) program, through
which NASA encourages commercialization of technologies that
have both public and private sector applications (see page 108),
has been particularly productive of advanced software development.
An example in the field of computational simulation is the work
of Computational Mechanics Company, Inc. (COMCO), Austin, Texas.
Over the past decade, COMCO has worked on several NASA SBIR contracts
for computational mechanics modeling and simulation software,
and a number of COMCO's products have successfully been commercialized.
The company's basic software is the PHLEX (PHLEX, ProPHLEX
Developers Toolkit, PHLEXsolid, and UNISIM are trademarks of
Computational Mechanics Company.) family of hp-adaptive finite
element analysis programs, a library of object-based modules
that may be linked and extended to create job-specific codes
across a broad spectrum of engineering disciplines. NASA's research
assistance was integral to the development of PHLEX, says COMCO;
several NASA SBIRs allowed the company to improve and expand
upon the PHLEX code and make it work for a variety of computational
mechanics problems, including problems in both fluid and solid
mechanics. Traditional general purpose finite element software
requires the expertise of an analyst to appreciate the quality
of the numerical simulations independently of the quality of
the design. PHLEX-based software is designed to remove the uncertainty
about the quality of the solution by estimating the solution's
error and producing, automatically, the optimal hp-adapted mesh
for the accuracy the user chooses.
A Texaco inspector performs a routine quality control check.
A commercial offshoot of COMCO's SBIR work is ProPHLEX Developers
Toolkit, introduced in 1995. The primary targeted users are major
industrial corporations (for mechanical design applications)
and universities (for research and mechanical engineering training).
Ford Motor Company has supported ongoing development to produce
a companion product, PHLEXsolid, and make it compatible with
NASTRAN, the NASA-developed standard finite element analysis
code used by Ford in auto design. Ford seeks to couple NASTRAN
capabilities with the hp-adaptive and Residual Error Estimation
features of the PHLEX library. Says a Ford official: "hp-adaptive
finite element analysis is one of the key enabling technologies
in Ford's drive to reduce the concept-to-market cycle."
Another spinoff product is UNISIM, a PHLEX-based code for
analyzing underground flows in oil reservoirs. Developed by COMCO
with funding from Texaco Inc, UNISIM is a finite element simulator
that combines the hp-adaptivity feature with parallel processing.
Designed to obtain accurate numerical pressure and saturation
solutions associated with large oil fields, the software models
the complicated dynamics of horizontal and vertical wells used
to inject water into reservoirs and force more of the oil to
the producing wells.
UNISIM simulation software produces imagery and data
for pressure and saturation solutions.
|
