Computational study of flow around a simplified car body

Emmanuel Guilmineau (1)

1 LHEEA - Laboratoire de recherche en Hydrodynamique, Énergétique et Environnement Atmosphérique

The Ahmed body is a simplified car used in automotive industry to investigate the influence of the flow structure on the drag. Wake flow is two-dimensional for low incidences of the rear slant, then becomes three-dimensional when the angle of the hatchback approaches 30° and reverts to two-dimensional behavior for angles higher than 30° where above this angle, a sudden drop in drag occurred. In this paper, we investigate numerically the flow around the Ahmed body for the base slant angles 25° and 35°. Results are compared with experimental data. The two-dimensional behavior of the flow, for the slant angle , is well predicted, whereas the transition of the wake to a fully three-dimensional, for the slant angle 25°, is not reproduced. Therefore, the flow around the Ahmed body with 25° slant angle can be considered an open challenge for turbulence modeling.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Emmanuel Guilmineau. Computational study of flow around a simplified car body. Journal of Wind Engineering and Industrial Aerodynamics, 2008, 96 (6-7), pp.1207-1217. ⟨10.1016/j.jweia.2007.06.041⟩. ⟨hal-04553632⟩