Abstract
Optimisation of the exterior shape of vehicles is one of the classical tasks of an aerodynamicist, where typically models of various scales are measured using wind-tunnel equipment. In recent years, parallel to this effort, numerical flow simulation has established itself as an accepted tool.
About 10 years ago numerical investigations were limited to very simplified geometric bodies, but today, the use of CFD is often integrated into the development chain as a standard application. Increased computer performance, clearly improved algorithms, as well as a high flexibility during modelling complex, production-like geometries supported this process. But mainly the realisation of a certain robustness coupled with the improved accuracy of the predictions led to the fact that the predication of the simulation recently has gained a much better reputation.
Recent developments within CFD and the procedures that have enabled a productive use of commercial software within the automotive industry are discussed. Besides addressing the important questions of processing geometry and generation of meshes, possibilities of automation of the process chain are also sketched.
With respect to a validation of the method, a basic 2D example is given as well as a comparison between numerical and experimental results for a 3D production car configuration.