CFD Applications using Wind-US - Glenn Research Center · CFD Applications using Wind-US ......
Transcript of CFD Applications using Wind-US - Glenn Research Center · CFD Applications using Wind-US ......
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Glenn Research Center
GTX Inlet
• Rocket-Based Combined Cycle (RBCC) Concept for single-stage to orbit (SSTO)
• Steady-state analyses
• Inlet Flow (Mach 6)– Support tunnel tests
– Examine design options
– Examine unstart sensitivities
– Examine bleed options
Researcher: John Slater (Inlet Branch)
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Glenn Research Center
3D Subsonic InletsDesign study on geometric parameters for 3D subsonic inletsResearcher: John Abbott (Inlet Branch)
Lower Lip Extension, LS/RDE
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1.15
1.2
1.25
1.3
1.35
0 0.25 0.5 0.75 1
αSEP=24o 26o 28o 32o 34o 36o
Static Upper LipSeparation
30o
Cruise Upper LipSeparation
V=1.75 V=2.00 V=2.25
38o40o
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Glenn Research Center
Active Inlet flow Control for Ultra-Intelligent Inlet/Engine Systems
Output:Tailored Inlet FlowField for OptimizedEngine Performance& Operability
Independently ControlledEffector Arrays 1% Fan Bleed
Off
On
Inlet Control
•Neural Net Models•Closed Loop Control
•Inlet•Variables:•Geometry•Inlet Air Flow•Mach Number•Angle of Attack•Sideslip
DistributedSensors ProvideFlow State Map
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Glenn Research Center
Modifications to increase test section to Mach 4
Existing Throat
Modified Throat
Researcher: John Slater (Inlet Branch)
10x10 SWT Second ThroatPD
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Glenn Research Center
Tandem Fan Nacelle
Matched design mass flow.
Streamlines stagnate above cowl highlight; however, no separation.
Uniform total pressure profile at fan face.
Fan Mach = 0.2636
Recovery: 0.9989
Mach contours
Researcher: John Slater (Inlet Branch)
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Glenn Research Center
Rocket Engine Exhaust
H2-O2 RocketPt = 500 psi, Tt=5540 R Cooled Panel
Ambient Air
Frozen chemistry, sevenspecies.
SST turbulence model.Mach contours shown.
Used to compute heattransfer from plume tocooled panel.
Good agreement with data.
Researcher: Nick Georgiadis (Nozzle Branch)
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Glenn Research Center
Supersonic Cruise Nozzle
Validation case for NASA’s NextGeneration Launch Technology.
Reference NASA LaRC nozzle atoff-design conditions.
SST turbulence model.Very good separated flow prediction.
Researcher: Teryn DalBello (Nozzle Branch)
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Glenn Research Center
Jet Noise Prediction
Researcher: Danielle Koch (Acoustics Branch)
Normalized Turbulence Kinetic Energy Distributions, Mach 0.9
PIV Data / WIND Predictions Acoustic Data / MGBK Predictions
- Jet noise predictions generated using WIND, and MGBKaeroacoustic code.
- Mean flow and k–ε results from WIND are input to MGBK.- Accurate prediction of location and magnitude of turbulence
kinetic energy is important if the mean flow results are usedto estimate jet noise.
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Glenn Research Center
Stanitz Elbow
• 90o rectangular elbow (Stanitz et al., NACA, 1953)
• Incompressible flow (Mach 0.26)
• Secondary flow without separation
• Simple geometry and accurate grid
• Inflow BC matches inflow boundary layer
• Outflow BC matches mass flow
• Data (Stanitz et al., 1953)– Inflow boundary layer profile
– Surface static pressures
– Rake total pressure contours
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Glenn Research Center
NASA VDC Inlet• M∞ = 2.35 ⇒ supersonic
• Mixed-compression inlet
• Axisymmetric CFD model
• No leaves, VGs, or struts
• Bleed slot (2.545% flow)
• Nozzle at exit for outflow– Match back-pressure of data
• Data (Saunders et al., 1993)– Centerbody static pressures
– Cowl static pressures
– Pressure recovery
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Glenn Research Center
CFD Objectives – Shock structure– Steady-state performance– Recovery –vs- mass flow
(cane curve)– Spillage– Bleed locations and amount– Best cowl lip and slot
configuration (DOE methods)– Off-design (Mach, α)
Parametric Inlet
Analyses has demonstrated need for:– Bleed models (adjustable mass flow)– Vortex generator models– Outflow boundary conditions
Researcher: John Slater (Inlet Branch)
External-compression, supersonic inlet
CFD used the design
CFD supporting testing and validation
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Glenn Research Center
“Optimized” Bleed Cane Curve
93.4%
92.0%
90.4%
88.2%
85.1%
DOE study improved the performance of the inlet over the engine flow sweep
Pslot = 3.5 psi, Pcorner= 4.0, Φaft = 30%
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0.70
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0.80
0.85
0.90
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84 86 88 90 92 94 96 98 100
Outflow (%)
Rec
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Goal
7Z6I
7Z6DOE
Baseline
Optimized
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Glenn Research Center
Interaction of Normal Shock with Bleed
MFR = 0.919
MFR = 0.919
MFR = 0.919
MFR = 0.908
2.4%
0.8%2.1%
2.1%
% of capture flow
MFR = 0.892
MFR = 0.876
MFR = 0.859
MFR = 0.841
NASA “1507” Inlet (B1)
3.5%
4.9%
5.9%
6.9%
7.9%
1.7%
2.4%
3.2%
1.0%
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