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
2
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
3
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
4
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
5
Wing-Body Results (M = 0.75)
6
Wing-Body Results (M = 0.75)
7
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
8
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
9
Wing-Body-Nacelle-PylonResults (M = 0.75)
10
Grid Dependency of Results
Fuselage Skin Friction Drag
Wing-Body ~72 countsWing-Body-Nacelle-Pylon ~77 counts
†
D ~ 5 counts
11
Wing-Body Pressure Distribution(M = 0.75, CL = 0.5)
12
Wing-Body-Nacelle-Pylon PressureDistribution
(M = 0.75, Incidence = 0.19)
13
Pylon and Nacelle PressureDistribution
(M = 0.75, Incidence = 0.19)
14
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