This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Calibration Study of CFD for Automotive Shapes and CD
Annotation ability available
Sector:
Language:
English
Abstract
An extensive calibration study has been initiated to assess the predictive ability of CFD (Computational Fluid Dynamics) for the aerodynamic design of automotive shapes. Several codes are being checked against a set of detailed wind tunnel measurements on ten car-like shapes. The objective is to assess the ability of numerical analysis to predict the CD (drag coefficient) influence of the rear end configuration. The study also provides a significant base of information for investigating discrepancies between predicted and measured flow fields and for assessing new numerical techniques.
This technical report compares STAR-CD predictions to the wind tunnel measurements. The initial results are quite encouraging. Calculated centerline pressure distributions on the front end, underbody and floor compare well for all ten shapes. Wake flow structures are in reasonable agreement for many of the configurations. Drag, lift, and pitching moment trends follow the experimental measurements. The predicted CD levels, however, are higher than the measurements and, despite the fine computational grid, modeling of the rear end flow is incorrect for some configurations.
Recommended Content
Authors
Topic
Citation
Williams, J., Quinlan, W., Hackett, J., Thompson, S. et al., "A Calibration Study of CFD for Automotive Shapes and CD," SAE Technical Paper 940323, 1994, https://doi.org/10.4271/940323.Also In
References
- Hucho, W. Sovran G. Aerodynamics of Road Vehicles Annual Review of Fluid Mechanics 1993 25 485 537
- Kobayashi, T. Kitoh K. A Review of CFD Methods and Their Application to Automobile Aerodynamics SAE 920338 February 1992
- Ahmed, S. R. A Critical Review of the CFD-Methods Available to Compute Flow Around Automobiles Innovation and Reliability in Automotive Design and Testing 3 1437 1456 April 1992
- Bangert, L. H. Johnson C. E. Schoop M. J. CFD Applications in F-22 Design AIAA 93-3055 July 1993
- Han, T. Y. A Navier-Stokes Analysis of Three-Dimensional Turbulent Flows Around a Bluff Body in Ground Proximity AIAA 88-3376 July 1988
- Hashiguchi, M. et al. Computational Study of the Wake Structure of a Simplified Ground-Vehicle Shape with Base Slant SAE 890597 February 1989
- Matsunaga, K. et al. Finite-Difference Simulation of 3D Vortical Flows Past Road Vehicles SAE 920339 February 1992
- Nouzawa, T. et al. Unsteady-Wake Analysis of the Aerodynamic Drag of a Notchback Model with Critical Afterbody Geometry SAE 920202 February 1992
- Yamada, A. Ito S. Computational Analysis of Flow Around a Simplified Vehicle-Like Body SAE 930293 March 1993
- Hutchings, B. J. Pien W. Computation of Three-Dimensional Vehicle Aerodynamics Using FLUENT/BFC Proc. 2nd International Conf. on Supercomputing Applications in the Automotive Industry Seville 233 255 Cray Research 1988
- Adey, P. C. Greaves J. R. A. The Application of a 3-D Aerodynamics Model to the Sterling 825 Body Shape and Comparison with Experimental Data SAE 880456 February 1988
- Shaw, C. T. Predicting Vehicle Aerodynamics Using Computational Fluid Dynamics - A User's Perspective SAE 880455 February 1988
- Malone, J. B. et al. Three-Dimensional Navier-Stokes Solution for a Car-Like Body AIAA 88-3769 July 1988
- Kawaguchi, K. et al. Computation Study of the Aerodynamic Behavior of a Three-Dimensional Car Configuration SAE 890598 February 1989
- Himeno, R. et al. Numerical Analysis of the Airflow around Automobiles Using Multi-Block Structured Grids SAE 900319 February 1990
- Ono, K. et al. Simultaneous Computation of the External Flow around a Car Body and the Internal Flow Through its Engine Compartment SAE 920342 February 1992
- Kataoka, T. et al. Numerical simulations of Road Vehicle Aerodynamics and Effect of Aerodynamic Devices SAE 910597 February 1991
- Shiozawa, H. et al. Numerical Analysis of the Effect of a Rear Spoiler on Flow Fields Around a Car Innovation and Reliability in Automotive Design and Testing 3 1479 1485 April 1992
- Bearman, P. W. Some Observations on Road Vehicle Wakes SAE 840301 February 1984
- Marvin, J. G. Accuracy Requirements and Benchmark Experiments for CFD Validation NASA-TM-100087 May 1988
- Hacked, J. E. et al. On the Influence of Ground Movement and Wheel Rotation in Tests on Modern Car Shapes SAE 870245 February 1987
- “STAR-CD Version 2.1 Manuals” Computational Dynamics Limited 1991
- Yakhot, V. Orsag S. A. et al. Development of Turbulence Models for Shear Flows by a Double Expansion Technique Physics of Fluids 4 7 1510 1992
- Franke, R. Rodi W. Schoenung B. Analysis of Experimental Vortex Shedding Data with Respect to Turbulence Modeling Seventh Symp. on Turbulent Shear Flows 24 4 1989