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Computational Fluid Dynamics (CFD) has found increasing use by aerodynamicists in recent years. Highly affordable computer hardware coupled with advances in computational techniques and availability of commercial CFD codes support this trend. However, as is true with any computer simulation, there is always a need for comparing aerodynamic CFD predictions extensively to the results measured in wind tunnel experiments. One such calibration study has been initiated by Ford Motor Company to assess the predictive ability of commercially available CFD codes for the aerodynamic design of automobile shapes. Several codes have been checked against a set of detailed wind tunnel measurements on a number of car shapes. The work is being continued to date. This study has provided a significant information base for comparison of predicted and measured flow fields.

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.