Predicting Automobile Aerodynamic Characteristics Using an iterative Viscous/Potential Flow Technique

An iterative viscous/potential flow calculation method is described in this paper. A potential-flow panel method is coupled with integral boundary layer methods. Simple linear doublet sheets are used to enclose the low-energy separated-flow region of the wake. Calculations for various body shapes demonstrate that unseparated flow pressure distributions are accurately calculated. Body lift trends are also properly computed for a simple body with separation only at the base and in close ground proximity. However, the prediction of average base pressure is only partially successful. The base pressures for a limited number of geometries, which include a Porsche 924, are properly predicted, but calculations for other shapes indicate that the separated-flow wake model must be improved for general body shapes.