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Accuracy of Drag Predictions on Cars Using CFD - Effect of Grid Refinement and Turbulence Models
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Abstract
Computations of the flow around a basic car shape, the Volvo ECC, have been done using different turbulence models: two lowRe k-ε model, the standard k-ε model and the IP and Gibson-Launder version of the Reynolds Stress Model (RSM). Results from the different computations are compared to windtunnel measurements of drag, pressure and velocity. The effect of the turbulence model on the accuracy of predicted pressure and drag is studied. To provide a basis for this work grid refinement studies have been performed to study the effect of mesh resolution and mesh quality on the error in pressure and drag. It is shown that mesh quality is important to preserve the order of the difference schemes but that the grid related error may be virtually eliminated. Further the computations show that a lowRe k-e model yields the best prediction of experimental data.
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Citation
Ramnefors, M., Bensryd, R., Holmberg, E., and Perzon, S., "Accuracy of Drag Predictions on Cars Using CFD - Effect of Grid Refinement and Turbulence Models," SAE Technical Paper 960681, 1996, https://doi.org/10.4271/960681.Also In
Vehicle Aerodynamics: Wind Tunnels, Cfd, Aeroacoustics, and Ground Transportation Systems
Number: SP-1145; Published: 1996-02-01
Number: SP-1145; Published: 1996-02-01
References
- Ramnefors, M. Sköldheden, T. 1994 “Aerodynamic Computation as Part of the Design Process” Volvo Technology Report, no 2 1994 46 53 Volvo, Sweden
- Landby, P. Ramnefors, M. 1994 “CFD as a Tool in Styling Vehicles” Proceedings Second CFDS International Users Conference Pittsburg 7 -9 December 1994 USA
- Ramnefors, M. Perzon, S. Davidson, L. 1994 “Accuracy in Drag Prediction on Automobiles” Proceedings Conference on “Vehicle Aerodynamics” Royal Aeronautical Society Loughborough University of Technology 18 - 19 July 1994 England
- Dahlander, P. Jönson A. 1995 “On truncation errors in generalised curvilinear coordinate systems” Chalmer University of Technology, Department of Thermo and Fluid Dynamics
- Perzon, S. Davidson, L. Ramnefors, M. 1995 “Computations on test case 2” 4'th ERCOFTAC Workshop on Refined Flow Modelling University of Kalsruhe 3 - 7 April 1995 Germany
- Daunius, O. 1995 “Computations on test case 4” 4'th ERCOFTAC Workshop on Refined Flow Modelling University of Kalsruhe 3 - 7 April 1995 Germany
- Perzon, S. Davidson, L. Ramnefors, M. 1995 “Reynolds stress modelling of flow separation on curved surfaces. A status report” Internal Report 95/12 Chalmers University of Technology, Department of Thermo and Fluid Dynamics
- Hodge, J.K. Stone, A.L. Miller, T.E. 1979 “Numerical Solution for Airfoils near Stall in Optimized Boundary-Fitted Curvilinear Coordinates” AIAA J. 19 458 464
- Fletcher, C.A.J. 1991 “Computational techniques for fluid dynamics” Springer-Verlag Berlin
- Thompson, J.F. Warsi, Z.U.A. Wayne Mastin, C. 1985 “Numerical grid generation” North-Holland, New York
- Leonard, B.P. 1994 “Comparison of truncation error on finite-difference and finite-volume formulations of convection terms” Applied Mathematic Modelling 18 46 50
- Launder, B.E. Sharma, B.T. 1974 “Application of the energy dissipation model of turbulence to the calculation of flow near a spinning disc” Lett Heat and Mass Transfer 1 131 138
- Chen, H.C. Patel, V.C. 1988 “Near-wall turbulence models for complex flows including separation” AIAA J june 641 648
- Naot, D. Shavit, A. Wolfshtein, M. 1970 “Interactions Between Components of the Turbulent Velocity Correlation Tensor” Israel J. Techn. 8 259
- Rotta, J.C. 1951 129 547 572
- Gibson, M.M. Launder, B.E. 1978 “Ground Effects on Pressure Fluctuations in the Atmospheric