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1http://fun3d.larc.nasa.govHiLiftPW-2 June 21-22, 2013
CFL3D and FUN3D Analysis of
HiLiftPW-2 Workshop Cases
Elizabeth M. Lee-Rausch & Christopher L. Rumsey
NASA Langley Research Center
2nd AIAA CFD High Lift Prediction Workshop (HiLiftPW-2)
Sponsored by the Applied Aerodynamics TC
San Diego, CA
June 22-23, 2013
2http://fun3d.larc.nasa.govHiLiftPW-2 June 21-22, 2013
CFD Code Descriptions
• CFL3D Structured-Grid Code
– Parallel 3D compressible cell-centered finite-volume RANS
– Full Navier-Stokes equations
– Upwind Roe flux-difference splitting for inviscid fluxes
– Spalart-Allmaras and SST turbulence models, fully-turbulent
– SST-Gamma-Re-Theta (GRET), transition
– Implicit local time-stepping using AF relaxation for linear system
– Restart computations from lower angles of attack
• FUN3D Unstructured-Grid Code
– Parallel 3D compressible finite-volume RANS for mixed-element meshes
– Full Navier-Stokes equations-node centered
– UMUSCL 0.5 scheme (Averaging + Upwind) for inviscid fluxes
– Spalart-Allmaras turbulence model, fully-turbulent
– Implicit local time-stepping using multi-color point Gauss-Seidel relaxation for
linear system
– Restart computations from lower angles of attack
3http://fun3d.larc.nasa.gov
Cases and Grids
HiLiftPW-2 June 21-22, 2013
Struct.
1 to 1 – A
(Boeing)
Unst.
Nodal - D
(UWYO/Cessna)
FUN3DSA
(Mixed)
CFL3D
(Case 1 only)
SA
SST (incomplete)
GRET (incomplete)
• Required Case 1 and Case 2
• Optional Case 3 not done
4http://fun3d.larc.nasa.govHiLiftPW-2 June 21-22, 2013
Coarse Medium Fine
Struct.
1-to-1 A
Boeing
11M 34M 105M
Mixed ver.
Unst. D
UWYO/Cessna
10M 31M 76M
Comparison of Grid Sizes
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Case 1 – FUN3D Grid Convergence, SA
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
ALPHA
CL
0 10 20 301
1.5
2
2.5
3
3.5
002.1 case1 FT coarse no tracks
002.1 case1 FT medium no tracks002.1 case1 FT fine no tracksExp. ETW
CD
CL
0.1 0.2 0.3 0.4 0.5 0.61
1.5
2
2.5
3
3.5
CM, CM25
CL
-0.6 -0.4 -0.2 01
1.5
2
2.5
3
3.5
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Case 1 – CFL3D Grid Convergence, SA
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
ALPHA
CL
0 10 20 301
1.5
2
2.5
3
3.5
002.2 case1 FT coarse no tracks002.2 case1 FT medium no tracks
002.2 case1 FT fine no tracksExp. ETW
CD
CL
0.1 0.2 0.3 0.4 0.5 0.61
1.5
2
2.5
3
3.5
CM, CM25
CL
-0.6 -0.4 -0.2 01
1.5
2
2.5
3
3.5
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Case 1 – CFL3D results, other models
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
Medium Grids
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Case 1 – Grid Convergence, SA
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
9http://fun3d.larc.nasa.gov
Case 1 – Grid Convergence, AoA=7
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
Note: Grid D (fine) was discovered to have
incorrect min spacing – so not of similar
family to C and M.
10http://fun3d.larc.nasa.gov
Case 1 – Grid Convergence, AoA=16
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
Note: Grid D (fine) was discovered to have
incorrect min spacing – so not of similar
family to C and M.
11http://fun3d.larc.nasa.gov
Case2 – Reynolds Number Study
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
ALPHA
CL
0 10 20 301
1.5
2
2.5
3
3.5
002.1 case2a (low Re) FT medium w tracks002.1 case2b (hi Re) FT medium w tracksExp. LSTW low Re
Exp. ETW hi Re
CD
CL
0.1 0.2 0.3 0.4 0.5 0.61
1.5
2
2.5
3
3.5
CM, CM25
CL
-0.6 -0.4 -0.2 01
1.5
2
2.5
3
3.5
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Case 1 Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 16deg
Medium Grids
FUN3D CFL3D
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FUN3D Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 16deg
Medium Grid
Case 1 Case 2b
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Case 1 Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 20deg
Medium Grids
FUN3D CFL3D
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FUN3D Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 20deg
Medium Grid
Case 1 Case 2b
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FUN3D Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 18.5deg
Medium Grid
Exp. Oil FlowCase 2a
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FUN3D Pressure Distributions
HiLiftPW-2 June 21-22, 2013
Case 1 Medium Grid
Eta = 0.45
Slat Main Flap
x
Cp
1640 1660 1680 1700 1720
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1400 1500 1600
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1360 1370 1380 1390 1400
-15
-10
-5
0
Black - 21 deg
Red - 7degBlue - 16degGreen - 18.5deg
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FUN3D Pressure Distributions
HiLiftPW-2 June 21-22, 2013
Case 2b
Eta = 0.45
Slat Main Flap
x
Cp
1640 1660 1680 1700 1720
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1400 1500 1600
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1360 1370 1380 1390 1400
-15
-10
-5
0
Black - 21 deg
Red - 7degBlue - 16degGreen - 18.5deg
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FUN3D Pressure Distributions
HiLiftPW-2 June 21-22, 2013
Case 1 Medium Grid
Eta = 0.75
Slat Main Flap
x
Cp
1840 1860 1880
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1650 1700 1750 1800 1850
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1630 1640 1650 1660 1670
-15
-10
-5
0
Black - 21 deg
Red - 7degBlue - 16degGreen - 18.5deg
20http://fun3d.larc.nasa.gov
FUN3D Pressure Distributions
HiLiftPW-2 June 21-22, 2013
Case 2b
Eta = 0.75
Slat Main Flap
x
Cp
1840 1860 1880
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1650 1700 1750 1800 1850
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
x
Cp
1630 1640 1650 1660 1670
-15
-10
-5
0
Black - 21 deg
Red - 7degBlue - 16degGreen - 18.5deg
21http://fun3d.larc.nasa.gov
Velocity contours over flap, AoA=7
HiLiftPW-2 June 21-22, 2013
Plane 2
22http://fun3d.larc.nasa.gov
Velocity profiles over flap, AoA=7
HiLiftPW-2 June 21-22, 2013
Note: exp data at low Re, shown for reference only
Plane 2
Case 1 Medium/Fine Grids
23http://fun3d.larc.nasa.gov
Effect of Re on velocity profiles, AoA=7
HiLiftPW-2 June 21-22, 2013
Plane 1-window B Plane 1-window D Plane 2-window D
Plane 2-window E Plane 3-window E Plane 3-window E
24http://fun3d.larc.nasa.gov
Summary (1)
• Grid convergence study (no brackets)¯ Structured grid and unstructured grid results with same
turbulence model (SA) compare reasonably well in forces/moments
¯ There is flap separation at all AoAs
¯ FUN3D on unstructured D grid shows more separation than CFL3D on structured A grid
¯ Maximum lift coefficient is over-predicted
¯ At higher alphas, there are larger differences between codes (esp. in the moment coefficient)
¯ CFL3D on structured A grid series captures wake profiles better than FUN3D on unstructured D grid series
HiLiftPW-2 June 21-22, 2013
25http://fun3d.larc.nasa.gov
Summary (2)
• Bracket study¯ Including brackets improves results (forces, moments,
surface pressures)
¯ General trends captured
¯ CL,max not predicted well due to early main wing separation
¯ Slat wakes not resolved on D grids
• Reynolds number study¯ General trends captured, but CL,max not predicted well
¯ Velocity profiles compare with experiment only qualitatively
HiLiftPW-2 June 21-22, 2013
26http://fun3d.larc.nasa.gov
N-2/3
CL
0 1E-05 2E-05
2.6
2.8
3
3.2
3.4
16 deg
Black - Workshop Grids
Red - 4th Adapted Grids
N-2/3
CD
0 1E-05 2E-05
0.26
0.28
0.3
0.32
0.34
16 deg
N-2/3
CM
0 1E-05 2E-05-0.7
-0.6
-0.5
-0.4
16 deg
Next Steps• Adjoint-based adaption : output functional L/D
– Off-body adaption
– C1 coarse and medium grids (SA model)
– AOA 16deg
– Four adaption cycles (4 additional adjoint and flow solutions)
HiLiftPW-2 June 21-22, 2013
11M16M31M
62M
27http://fun3d.larc.nasa.gov
C1 Medium Grid Adaption η=70%
HiLiftPW-2 June 21-22, 2013
Original Grid – 31M nodes
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C1 Medium Grid Adaption η=70%
HiLiftPW-2 June 21-22, 2013
Adapted 4 – 62M nodes
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C1 Medium Grid Adaption Flap Cp
HiLiftPW-2 June 21-22, 2013
Orig. Grid – 31M nodes : Adapted 4 – 62M nodes
η=72% η=82% η=89%
x
cp
,c
p_
ET
W_R
UN
23
8
1800 1820 1840 1860 1880
-4
-2
0
2
Symbols - Exp.Black - C1 Med. GridRed - Adapted Grid
x
cp
,c
p_
ET
W_R
UN
23
8
1880 1900 1920
-4
-2
0
2
Symbols - Exp.Black - C1 Med. GridRed - Adapted Grid
x
cp
,c
p_
ET
W_R
UN
23
8
1920 1940 1960
-4
-2
0
2
Symbols - Exp.Black - C1 Med. GridRed - Adapted Grid
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Effect of Turb. Model on Flap Cp
HiLiftPW-2 June 21-22, 2013
SADM – SA model with Dacles-Mariani correction
η=89%
x
cp
,cp
_E
TW
_R
UN
23
8
1920 1940 1960
-4
-2
0
2
Red - 4th Adapted Grid SA
Blue - 4th Adapted Grid SADM
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Backup Slides
HiLiftPW-2 June 21-22, 2013
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FUN3D Residual Convergence
HiLiftPW-2 June 21-22, 2013
Iteration
R_
1,R
_6
C_
L
C_
D
0 20000 40000 6000010
-10
10-8
10-6
10-4
10-2
100
102
104
1
1.5
2
2.5
3
3.5
4
4.5
5
0
0.1
0.2
0.3
0.4
0.5
HiLiftPW2 DLR-F11 Case1 Med. SA 22.4 deg
7deg
16deg18.5deg
20deg 21deg 22.4deg
C1 Medium Grid Polar
R6
R1
33http://fun3d.larc.nasa.gov
ITER
RE
SID
M-1
CL
CD
0 50000 100000 15000010
-10
10-8
10-6
10-4
10-2
100
102
104
1
1.5
2
2.5
3
3.5
4
4.5
5
0
0.1
0.2
0.3
0.4
0.5
7deg
16deg
18.5deg20deg
21deg22.4deg
CFL3D Residual Convergence
HiLiftPW-2 June 21-22, 2013
C1 Medium Grid Polar
34http://fun3d.larc.nasa.govHiLiftPW-2 June 21-22, 2013
Objectives– Assess the numerical prediction capability (meshing, numerics, turbulence modeling,
high-performance computing requirements, etc.) of current-generation CFD
technology/codes for swept, medium-to-high-aspect ratio wings for landing/take-off
(high-lift) configurations.
– Develop practical modeling guidelines for CFD prediction of high-lift flow fields.
– Determine the elements of high-lift flow physics that are critical for modeling to enable
the development of more accurate prediction methods and tools.
– Enhance CFD prediction capability for practical high-lift aerodynamic design and
optimization.
Focus– The HiLiftPW-2 test cases are based on the European High Lift Programme
(EUROLIFT) DLR F11 high-lift configuration.
• Representative of a commercial wide-body twin-jet high-lift configuration
• 3 elements : full-span slat, main and full-span flap
• Landing configuration : slat 26.5 degs and flap 32 degs
– A significant amount of high-quality surface and flow field data are available, including
data for an assessment of Reynolds number scale effects.
• Force and moment (ETW and B-LSWT)
• Surface pressures (ETW and B-LSWT)
• PIV and oil flow (B-LSWT)
HiLiftPW-2 - Rehearsal Background
35http://fun3d.larc.nasa.gov
HiLiftPW-2 – DLR F11
HiLiftPW-2 June 21-22, 2013
PIV PlanesPressure Tap Stations
η=17.6%
η=70%
η=87.4%
η=44.9%___
η=75.1% ___
36http://fun3d.larc.nasa.govHiLiftPW-2 June 21-22, 2013
• Case 1 : Grid convergence study (required)
– Mach = 0.175, free-air
– Angles-of-attack to be computed (deg) = 7 and 16 (18.5, 20, 21 and 22.4)
– ReMAC = 15.1 M, fully turbulent
– DLR F11 "Config 2" - Slat 26.5 deg, Flap 32 deg (Wing/Body/HL system + SOB Flap Seal)
– Coarse, medium, fine and extra-fine
• Case 2a and 2b: Reynolds number study (required)
– Mach = 0.175, free-air
– Angles-of-attack to be computed (deg) = 0, 7, 12, 16, 18.5, 19, 20 and 21
– ReMAC = 1.35M (Case2a) and 15.1 M(Case2b), fully turbulent
– Medium density mesh from Grid Convergence Study
– DLR F11 "Config 4" - Slat 26.5 deg, Flap 32 deg (Config 2 + Slat Tracks and Flap Track Fairings)
• Case 2c (OPTIONAL) - Low Reynolds Number Condition with Transition
• Case 3 (OPTIONAL) - Full Configuration Study
• Case 4 (OPTIONAL) - Turbulence Model Grid-Convergence Verification Study
HiLiftPW-2 - Rehearsal Background
37http://fun3d.larc.nasa.gov
Case 1 Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 7deg
Medium Grids
FUN3D CFL3D
38http://fun3d.larc.nasa.gov
FUN3D Surface Restricted Streamlines
HiLiftPW-2 June 21-22, 2013
AOA 7deg
Medium Grid
Case 1 Case 2b
39http://fun3d.larc.nasa.gov
Case 1 – Grid Convergence, AoA=20
HiLiftPW-2 June 21-22, 2013
Lift Drag Pitching Moment
Note: Grid D (fine) was discovered to have
incorrect min spacing – so not of similar
family to C and M.
40http://fun3d.larc.nasa.gov
C1 Medium Grid Adaption η=70%
HiLiftPW-2 June 21-22, 2013
Adapted 1 – 37M nodes
41http://fun3d.larc.nasa.gov
C1 Medium Grid Adaption η=70%
HiLiftPW-2 June 21-22, 2013
Adapted 2 – 42M nodes