Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-1A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

2nd AIAA CFD Drag Prediction Workshop

NLR resultsobtained using

the multiblock structured flow solverENSOLV

2nd AIAA CFD Drag Prediction Workshop2nd AIAA CFD Drag Prediction Workshop

NLR resultsNLR resultsobtained usingobtained using

the multiblock structured flow solverthe multiblock structured flow solverENSOLVENSOLV

O.J. BoelensFluid Dynamics Division

Department of Computational Fluid Dynamics and Aero-elasticity

National Aerospace Laboratory, NLR

The Netherlands

O.J. BoelensO.J. BoelensFluid Dynamics DivisionFluid Dynamics Division

Department of Computational Fluid Dynamics and Aero-elasticityDepartment of Computational Fluid Dynamics and Aero-elasticity

National Aerospace Laboratory, NLRNational Aerospace Laboratory, NLR

The NetherlandsThe Netherlands

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-2A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)CFD MethodNLR results (ENSOLVNLR results (ENSOLV))CFD MethodCFD Method

n ENSOLV (part of NLR’s flow simulation system ENFLOW)

– Time-dependent Reynolds-averaged Navier-Stokesequations

– Cell-centred, central difference, finite volume scheme

– (Pseudo) time integration by explicit Runge-Kutta schemeto obtain steady-state solution

– Artificial dissipation (scalar and matrix) to prevent odd-evendecoupling

– Local time stepping, multi-grid and residual averaging toaccelerate convergence

nn ENSOLV (part of ENSOLV (part of NLRNLR’’s s flow simulation system ENFLOW)flow simulation system ENFLOW)

–– Time-dependent Reynolds-averaged Time-dependent Reynolds-averaged NavierNavier-Stokes-Stokesequationsequations

–– Cell-centred, central difference, finite volume schemeCell-centred, central difference, finite volume scheme

–– (Pseudo) time integration by explicit (Pseudo) time integration by explicit RungeRunge--Kutta Kutta schemeschemeto obtain steady-state solutionto obtain steady-state solution

–– Artificial dissipation (scalar and matrix) to prevent odd-evenArtificial dissipation (scalar and matrix) to prevent odd-evendecouplingdecoupling

–– Local time stepping, multi-grid and residual averaging toLocal time stepping, multi-grid and residual averaging toaccelerate convergenceaccelerate convergence

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-3A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)CFD MethodNLR results (ENSOLVNLR results (ENSOLV))CFD MethodCFD Method

n ENSOLV (part of NLR’s flow simulation system ENFLOW)

– Original k-w turbulence model as proposed by Wilcox

– Slight modification by introduction of ‘cross diffusion’ term toeliminate free-stream dependency of w

– Solve t=1/(w+w0) instead of w, to remove singularbehaviour of w at solid walls

– Production term in k-equation has been limited to preventunphysical high values of k near stagnation point

nn ENSOLV (part of ENSOLV (part of NLRNLR’’s s flow simulation system ENFLOW)flow simulation system ENFLOW)

–– Original Original k-k-ww turbulence model as proposed by Wilcox turbulence model as proposed by Wilcox

–– Slight modification by introduction of Slight modification by introduction of ‘‘cross diffusioncross diffusion’’ term to term toeliminate free-stream dependency of eliminate free-stream dependency of ww

–– Solve Solve tt=1/(=1/(ww++ww00) instead of ) instead of ww, to remove singular, to remove singularbehaviour of behaviour of ww at solid walls at solid walls

–– Production term in k-equation has been limited to preventProduction term in k-equation has been limited to preventunphysical high values of k near stagnation pointunphysical high values of k near stagnation point

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-4A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)GridNLR results (ENSOLVNLR results (ENSOLV))GridGrid

n ICEM CFD multi-block C-topology grids for wing/body andwing/body/pylon/nacelle

nn ICEM CFD multi-block C-topology grids for wing/body andICEM CFD multi-block C-topology grids for wing/body andwing/body/pylon/nacellewing/body/pylon/nacelle

Coarse: 3.3 M elementsCoarse: 3.3 M elements

Medium: 5.5 M elementsMedium: 5.5 M elements

Fine: 10 M elementsFine: 10 M elements

Coarse: 4.5 M elementsCoarse: 4.5 M elements

Medium: 8.3 M elementsMedium: 8.3 M elements

Fine: 13.7 M elementsFine: 13.7 M elements

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-5A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Solution informationNLRNLR results results (ENSOLV (ENSOLV))Solution informationSolution information

n Computer platform: NLR’s NEC SX-5/8B parallel vector super computer– Operating system: SUPER-UX sx5 11.1 E SX-5/8B– Compiler: FORTRAN90/SX Version 2.45 for SX-5

n Number of processors used (1-6) was such that complete simulationcould be carried out within one night (12 h)

nn Computer platform: Computer platform: NLRNLR’’s s NEC SX-5/8B parallel vector super computerNEC SX-5/8B parallel vector super computer–– Operating system: SUPER-UX sx5 11.1 E SX-5/8BOperating system: SUPER-UX sx5 11.1 E SX-5/8B–– Compiler: FORTRAN90/SX Version 2.45 for SX-5Compiler: FORTRAN90/SX Version 2.45 for SX-5

nn Number of processors used (1-6) was such that complete simulationNumber of processors used (1-6) was such that complete simulationcould be carried out within one night (12 h)could be carried out within one night (12 h)

CPU (h)wb

wbnp 27.847.166.4

Mem (GByte)2.54.17.5

3.35.48.4

10001000

125012501250

15001000

1500 15001500

1500

13.522.918.5

1000 (1 MG)1000 (1 MG)

750

1250 (1MG)1250 (1MG)

10001500

1500 (1 MG)1500 (1MG)

1500

15001500

coarsemediumfine

fine

coarsemedium

Level 1 Level 2 Level 3 Const. CL CPU (h)wb

wbnp 27.847.166.4

Mem (GByte)2.54.17.5

3.35.48.4

10001000

125012501250

15001000

1500 15001500

1500

13.522.918.5

1000 (1 MG)1000 (1 MG)

750

1250 (1MG)1250 (1MG)

10001500

1500 (1 MG)1500 (1MG)

1500

15001500

coarsemediumfine

fine

coarsemedium

Level 1 Level 2 Level 3 Const. CL

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-6A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 1: Single point grid convergence studyNLRNLR results results (ENSOLV (ENSOLV))Case 1: Single point grid convergence studyCase 1: Single point grid convergence study

n Mach = 0.75

n Reynolds Number = 3x106

n Lift Coefficient = 0.500±0.001

n “Fully turbulent” solution

nn Mach = 0.75Mach = 0.75

nn Reynolds Number = 3x10Reynolds Number = 3x1066

nn Lift Coefficient = 0.500Lift Coefficient = 0.500±±0.0010.001

nn ““Fully turbulentFully turbulent”” solution solution

CD installation

Coarse: 0.0046Medium: 0.0054Fine: 0.0051

Experiment: 0.0043

CD installation

Coarse: 0.0046Medium: 0.0054Fine: 0.0051

Experiment: 0.0043

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-7A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 1: Single point grid convergence study (wb)NLRNLR results results (ENSOLV (ENSOLV))Case 1: Single point grid convergence study (Case 1: Single point grid convergence study (wbwb))

Coarse: 3.3 M elementsCoarse: 3.3 M elements Medium: 5.5 M elementsMedium: 5.5 M elements Fine: 10 M elementsFine: 10 M elements

y+y+

CpCp

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-8A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 1: Single point grid convergence study (wbnp)NLRNLR results results (ENSOLV (ENSOLV))Case 1: Single point grid convergence study (Case 1: Single point grid convergence study (wbnpwbnp))

Coarse: 4.5 M elementsCoarse: 4.5 M elements Medium: 8.3 M elementsMedium: 8.3 M elements Fine: 13.7 M elementsFine: 13.7 M elements

y+y+

CpCp

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-9A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 1: Single point grid convergence study (wb)NLRNLR results results (ENSOLV (ENSOLV))Case 1: Single point grid convergence study (Case 1: Single point grid convergence study (wbwb))

y/b=0.331y/b=0.331 y/b=0.514y/b=0.514 Experiment Alpha=0.490 CL=0.4984

Experiment Alpha=0.490 CL=0.4984

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-10A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Trip locationNLRNLR results results (ENSOLV (ENSOLV))Trip locationTrip location

n Lower surface– 25 % chord

n Upper surface– 5 % chord at root– 15 % chord at kink– 15 % chord at

h=0.844– 5% chord at tip

nn Lower surfaceLower surface–– 25 % chord25 % chord

nn Upper surfaceUpper surface–– 5 % chord at root5 % chord at root–– 15 % chord at kink15 % chord at kink–– 15 % chord at15 % chord at

hh=0.844=0.844–– 5% chord at tip5% chord at tip

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-11A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 2: Drag PolarNLRNLR results results (ENSOLV (ENSOLV))Case 2: Drag PolarCase 2: Drag Polar

n Mach = 0.75

n Reynolds Number = 3x106

n Angle of Attack = -3, -2, -1.5, -1, 0, 1, 1.5°

n “Tripped” solution

nn Mach = 0.75Mach = 0.75

nn Reynolds Number = 3x10Reynolds Number = 3x1066

nn Angle of Attack = -3, -2, -1.5, -1, 0, 1, 1.5Angle of Attack = -3, -2, -1.5, -1, 0, 1, 1.5°°

nn ““TrippedTripped”” solution solution

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-12A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 2: Drag Polar (wb)NLRNLR results results (ENSOLV (ENSOLV))Case 2: Drag Polar (Case 2: Drag Polar (wbwb))

y/b=0.331y/b=0.331 y/b=0.514y/b=0.514 Experiment Alpha=0.490 CL=0.4984

Experiment Alpha=0.490 CL=0.4984

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-13A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 3: Effect of transitionNLRNLR results results (ENSOLV (ENSOLV))Case 3: Effect of transitionCase 3: Effect of transition

n Mach = 0.75

n Reynolds Number = 3x106

n Lift Coefficient = 0.500±0.001

n “Fully turbulent” vs. “Tripped” solution

nn Mach = 0.75Mach = 0.75

nn Reynolds Number = 3x10Reynolds Number = 3x1066

nn Lift Coefficient = 0.500Lift Coefficient = 0.500±±0.0010.001

nn ““Fully turbulentFully turbulent”” vsvs. . ““TrippedTripped”” solutionsolution

CD installation

Turbulent: 0.0054Tripped: 0.0054

Experiment: 0.0043

CD installation

Turbulent: 0.0054Tripped: 0.0054

Experiment: 0.0043

Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR

DXXX-14A2nd AIAA Drag Prediction Workshop, June 21-22, 2003, Orlando2nd AIAA 2nd AIAA DragDrag PredictionPrediction Workshop, Workshop, June June 21-22, 2003, 21-22, 2003, OrlandoOrlando

NLR results (ENSOLV)Case 3: Effect of transitionNLRNLR results results (ENSOLV (ENSOLV))Case 3: Effect of transitionCase 3: Effect of transition

y/b=0.331y/b=0.331 y/b=0.514y/b=0.514 Experiment Alpha=0.490 CL=0.4984

Experiment Alpha=0.490 CL=0.4984