space shuttle and launch pad lift-off debris transport ... · jerry radkejerry radke++, and peter...
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Space Shuttle and Launch Pad LiftSpace Shuttle and Launch Pad Lift--Off DebrisOff DebrisTransport AnalysisTransport Analysis –– SRB PlumeSRB Plume--DrivenDriven
Jeff West*, Louise Strutzenberg*,Jeff West*, Louise Strutzenberg*,Sam Dougherty^Sam Dougherty^Jerry RadkeJerry Radke++, and Peter Liever, and Peter Liever++
*NASA/MSFC, ^ERC/Jacobs ESTS,*NASA/MSFC, ^ERC/Jacobs ESTS, ++CFDRCCFDRC
18th Annual Thermal and Fluids Analysis Workshop18th Annual Thermal and Fluids Analysis WorkshopNASA Glenn Research Center September 2007NASA Glenn Research Center September 2007TFAWS 07
Shuttle Lift-Off DebrisSeptember 2007
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Need: Determine the possible size, speed, impactlocation, and impact energy of potential debris.
Approach:
1. Use computational fluid dynamics (CFD)techniques with debris trajectory tracking tools toanalyze potential debris events:
• simulate Ground winds, gravity, and the Shuttleplume flow interactions with the Launch Facility atLift-Off.
2. Identify and control every possible source of debrisliberation.
Virtual engineering simulations to validate risk mitigation strategy and toreduce risk to the Vehicle posed by debris.
Virtual engineering simulations to validate risk mitigation strategy and toreduce risk to the Vehicle posed by debris.
LiftLift--Off Debris Transport AnalysisOff Debris Transport Analysis
TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
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STS-107 SRB CHAMBER PRESSURE PROFILE (RECONSTRUCTED WITH MODEL5)
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0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
TIME (SEC)
PR
ES
SU
RE
(PS
IA)
LEFT SRB RECONSTRUCTED
LEFT SRB MEASURED DATA
RIGHT SRB RECONSTRUCED
RIGHT SRB MEASURED DATA
LiftLift--Off CFD Modeling ApproachOff CFD Modeling ApproachRequirements: Model quasi steady-state time slices simulating
Lift-Off sequence – SSME Start, SRBs at Full Thrust, Lift-Off,Throttle-Up, Performance Enhancements Climb-Out, Vehicle Drift
SRB Pc’s
SSME Pc’s
Note: Vehicle drifts North due to the SSME thrust vectorNorth TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
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North
a. T0 + 4 sec b. T0 + 3 sec c. T0 + 1.9 sec
Northa. T0 + 1.9 sec b. T0 + 3 sec
Critical SRB Plume InteractionsCritical SRB Plume Interactions
TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
Note: SRB plumes impinge on holddown post/haunches below.
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Matrix of Cycle 2 CFD Points North Drift (Nominal)
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0 5 10 15 20 25 30 35 40 45 50 55 60 65
Drift North (ft)
Hei
ght(
ft)
Cycle 1 SeriesSTS-115 BET
SSME No. 2 OutTrajectory 1 Pre-STS-1
Cycle 16.4 % Acoustic TestsCycle 2 Min Points
Cycle 2 Mid PointsCycle 2 Max PointsSTS-5 BET
West Drift 'Worst Case'STS-98 BETSTS-114 BET
STS-87 BETSTS-113 BETSTS-116 BET
STS-117 BET
LiftLift--Off CFDOff CFD ‘‘Design of ExperimentDesign of Experiment’’
Note: With the STS-117 flight came a new ‘min’ drift envelope.
A ‘Min – Mid – Max’ Drift strategy
Particulate boundary
Gas boundary
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Matrix of SSLV Trajectory Points (PE)
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0 5 10 15 20 25 30 35
Drift North (ft)
Hei
ght
(ft)
STS-115 BET
STS-5 BET (Ref.)
STS-98 BET
STS-114 BET
STS-87 BET
STS-106 BET
STS-113 BET
STS-121 BET
STS-116 BET
STS-117 BET
Matrix of Cycle 2 Points West Drift 'Worst Case'
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0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
Drift West (ft)
He
ight
(ft)
from 6.4 % Acoustics TestsStandard North Drift
TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
Finding Sensitivities to DriftFinding Sensitivities to Drift
Emphasis - Return-to flight since STS-114 Includes ‘worst-case’ lateral drift
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Plumeimpingement onthe North HDPBlast Shields iscaptured (inclosed position).
Plumeimpingement onthe North HDPBlast Shields iscaptured (inclosed position).
TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
Full 3Full 3--D, SingleD, Single--SRB,SRB, ½½ -- SRB StrategySRB Strategy
½ - SRB Model, up to 60 million grid cells
Full SRB Model, up to 120million grid cells
Full 3-D Vehicle andLaunch Pad Model, up to
~ 100 million grid cells(not shown here, de-
featured as necessary tomanage total model size)
Use 3-Tiered LO DTAProcess: Startscreening of debrissources with ½ - SRBModel and all driftmatrix points, go toFull SRB Model, andthen to Full 3-D Modelonly as necessary forSRB plume-drivendebris.
Use 3-Tiered LO DTAProcess: Startscreening of debrissources with ½ - SRBModel and all driftmatrix points, go toFull SRB Model, andthen to Full 3-D Modelonly as necessary forSRB plume-drivendebris.
8TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
Potential Holddown Nut Shard DebrisPotential Holddown Nut Shard Debris
Example: a high BNdebris particle isreleased –deterministic trackingwhere can it go from8 possible releasepoints (post holes).
Example: a high BNdebris particle isreleased –deterministic trackingwhere can it go from8 possible releasepoints (post holes).
Trajectories colored by particle velocity.
9TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
Potential Holddown Nut Shard DebrisPotential Holddown Nut Shard DebrisNote: The high BN debris example: six days using 128 cpu’s of the Columbia super-computerat NASA/Ames each CFD case shown. Memory usage measured just under 200 gigabytes.
Debris tracing resultsexecuted serially underRedhat Linux on an AMDOpteron (tm) Processor250 with approximately32 gigabytes RAM, andg95/g++ compilers(thousands of particletrajectories).
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Concluding Remarks:1. The three-tiered analysis approach using Symmetric ½ -
SRB, Full SRB, and Full 3-D Integrated Shuttle andLaunch Pad CFD models for assessing potential debrishas been described.
2. Key ‘design-of experiment’ considerations for potentialSRB plume-driven debris analyses have been related:
• This for an example SRB plume-driven potentialdebris case presently in analysis for risk mitigation.
3. Lift-Off Debris Transport Analysis is in progress tosupport Shuttle launch and flight operations:
• To be based on a series of many potential debrisparticle trajectory runs.
TFAWS 07Shuttle Lift-Off DebrisSeptember 2007
LiftLift--Off Debris Transport AnalysisOff Debris Transport Analysis