Parallel CFD Supporting NASA's Space ope0 Mission ... CFD Supporting NASA's Space ope0 Mission...
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Parallel CFD Supporting NASA's Space o p e 0 Mission Directorate I
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Reynaldo J. Gomez Ill EGIAeroscience & Flight Mechanics NASA Johnson Space Center Houston,Texas April 2 1 ,2008
https://ntrs.nasa.gov/search.jsp?R=20100017498 2018-05-24T03:52:53+00:00Z
Design Development ARC wind tunnel tests
Operations NAS+CFD
Retirement FY 2010
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STS-70 & subs
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1982 .C.t..Ct.C+19~L).I ..... *I.*.t. 1994............+.L. 3000
SSME *a
Space flight
Shuttle engines
advanced Main - . engine Englue I shase II + redesian I
* OVERFLOW t .8 - Buning
OVERFLOW 1.6 * OVERFLOW Z O 2002.
* CGT 0. l a . PEGASUS 5
+ OVERFLOW-D 5 .
OVERFLOW 2.1
1980 1985 1990 1995 2000 2005 20 I0 300,000 grid points Proof of concept
16.2 million grid points 96.4 million grid points Matched flight derived wing Detailed airloads used for loads within 5% redesigns & flight support
Parallel computing from prelaunch to landing On-orbit Assessments
Hypervelocity Orbital Debris
I ransonic airloads
Gap F~ller t21-OBSS-2#01
A = 1 28 inches +/-0 10 I3 = 0 37 ~nches +/4110 C=024knches-cS 0 = 0.58 mnc@ 05 05 .
E = 120 ~nch 1-0.10 F = O 3p inches +I-0 05 C3 = 2 30 ImUes %&0> 15 '"- H 7 o.q~&&i-@g@ 2. - '.
AIM-2003- 1248 Contingency Abort
Many External Tank redesign assessments used solutions run on Columbia
-- Modified Aft Longeron --I
Multiple icelfrost ramp redesigns Ascent & entry windows airloads Discrete airloads data book updates Venting database updates Aerothermal support & others
RCS TyveP covers
Bipod Ramp Removal
+Z Aerovent Modification
LO, feedline bracket redesigns
NSTS 08303 day of launch ice ball launch commit tool developed by Stuart RogersIARC NAS-07-004
NSTS 08303 Rev D, Change 13 Iceball Allowable
Rarefied Direct Simulation Monte Carlo Simulations
4 F. E. Lumpkin et al . - 27th JANNAF
Conference 2003
HubbIe Servicing Mission Support
Venting of the airlock into the payload bay can overload the HST solar arrays. DSMC simulations are used to redesign vents and specify vent rates to minimize risks to the hardware. rn
LeBeau, G.J., and Lumpkin, F. E., Ill, "Application highlights of the DSMC Analysis Code (DAC) software for simulating rarefied flows", Computer Methods in Applied Mechanics and Engineering, 1 9 1,595-609,200 I.
Orbital debris hypervelocity impacts > 3 kmlsec
=IL 1 nrrr-m-mpgy
1 i - 2m 'am-mm
v
Figure 1. Stuffed Whipple shield schematic, and a Stuffed Whipple shield impact test (NASA JSC photo).
Shuttle support CFD tools developed on vector machines and transitioned to parallel architectures
Parallel Development
Engineering capability (DOF) doubling every 2 years
1989: O(1 05) DOF 2009: 0( 1 08) DOF
W e went to the moon without CFD or parallel computers.Why do we need them now?
Reduce number of physical testsL and improve relevance when you do test
Nearly 1 00,000 hours ( l I years) of Shuttle wind tunnel testing Many facilities have shut down or been mothballed
Provides flight increments1 environments that cannot be obtained otherwise
Verification &Validation requirements are
Guide forverification andvalidation of Computational Fluid Dynamics Simulations, AlAA G-077, 1 998.
Columbia Accident lnvestigation Board Report,Volume I, August 2003.
A Renewed Commitment to Exce1lence:An Assessment of the NASA Agency-wide Applicability of the Columbia Accident lnvestigation Report, PB2005- 100968, January 30,2004.
Standard for Models and Simulations, NASA-STD-7009, July, I I,
. . . and there is still more work to do.
Some STS- I flight anomalies are still beyond current CFD tool capabilities, e.g.
Acoustics and heating on complex configurations with strong shock wave-boundary layer interactions
RCSIaerolthermal interactions
Physical models (turbulence, chemistry, ...) are key limitations that need to be improved.
Uncertainty quantification (where are the CFD error bars?)