Drag Prediction of theDLR-F6 Configuration

2nd AIAA CFD Drag Prediction Workshop, 21-22 June, Orlando, FL

Georg May, Dr. Edwin van der Weide,Sriram Shankaran, Prof. Antony Jameson

Prof. Luigi Martinelli

Stanford University

Princeton University

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Multi-Block Structured CodeFLO107-MB

• Cell-Centered Finite Volume Scheme• H-CUSP Scheme for Convective Fluxes• SLIP Construction• Central Discretization for Viscous Fluxes• Runge-Kutta Time Stepping• Multigrid, Implicit Residual Smoothing, Local

Time Stepping• SPMD-Parallel Using MPI

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Turbulence Modeling

• Wilcox k - Model

• Segregated (Single Grid)

• Same Algorithm as for LaminarVariables (But Only 1st Order Diffusion)

• Point-Implicit Treatment of SourceTerms

• Fully Turbulent Flow

†

w

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Computer Architectures

• SGI Origin (IRIX 6.5), 32 Processors, 15GB Memory• Linux (2.4.18) Beowulf Cluster, 48 Nodes, ~1GB Memory per Node

Grids: ICEM Block-Structured

13.710Fine

8.55.5Medium

4.63.3Coarse

WBNPWB

Cells inMillion

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Wing-Body Results (M = 0.75)

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Wing-Body Results (M = 0.75)

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Wing-Body Results(M = 0.75, CL = 0.5)

-0.131

0.0128

0.0169

0.0297

0.32

Medium

-0.121-0.136CM

0.0139CDf

0.0169CDpr

0.02950.0308CD

0.520.23Incidence

ExperimentCoarse

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Wing-Body Results(M = 0.75, CL = 0.5)

• We Have a Separation Zone Near the Wing Root

Eye ~ 7mm/15mmfrom TE and WF Intersection,respectively

Size: ~ 73mm upstream of TE (at Wing Root) ~ 22 mm maximum extension of separating Streamline

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Wing-Body-Nacelle-PylonResults (M = 0.75)

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Grid Dependency of Results

Fuselage Skin Friction Drag

Wing-Body ~72 countsWing-Body-Nacelle-Pylon ~77 counts

†

D ~ 5 counts

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Wing-Body Pressure Distribution(M = 0.75, CL = 0.5)

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Wing-Body-Nacelle-Pylon PressureDistribution

(M = 0.75, Incidence = 0.19)

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Pylon and Nacelle PressureDistribution

(M = 0.75, Incidence = 0.19)

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Summary

• Correct Lift Slope and Polar Shape

• Good Agreement in Total Drag for Wing-Bodyconfiguration

• Deviation in Total Drag for Wing-Body-Nacelle-Pylon configuration likely due to GridDependency