Virtual Aerodynamic Engineering at GM Europe Development of the 2006 OPEL Corsa

Modern development in the automotive industry is strongly effected by fast turnaround times due to shorter development cycles for every new product. This leads to a reduction of more and more prototypes. Under these challenging circumstances traditional, hardware based development approaches often reach their limits. Together with new CAE tools the lack of resources and information can be faced.

This paper will describe how CFD simulation (Computational Fluid Dynamics) cooperates with traditional wind tunnel tests to reduce cost and provide even more valuable information. The efficient combination of both tools is the key for best aerodynamic optimized vehicles. In CFD the external aerodynamics of a certain styling (aerodynamic coefficients, flow field visualization) is generated even before any hardware prototypes are available. This allows the development engineer to rank different styling studies and a pre-optimization of selected themes prior to wind tunnel testing. Final optimization of the identified areas of improvement is done in the wind tunnel. Further areas of investigation in the early design phase are wind forces on body parts and aero-acoustic phenomena of components.

Wind loads on body parts are provided to support structural analysis for proper design. The aero-acoustic influence of components is analyzed and potential changes can be realized easily in the early development phase.

By today the impact of simulation in the vehicle development of external aerodynamics has increased significantly and will increase further with growing computer resources.