Aerodynamic study on the vehicle rear shape parameters with respect to ground simulation

Autoren

Chenyi Zhang, IVK, Universität Stuttgart;
Daniel Stoll, Timo Kuthada, Jochen Wiedemann, FKFS

Jahr

2019

Zusammenfassung

The automotive market today is being divided into more detailed segments than before to meet the diverse demand of customers. Correspondingly, the vehicle basic shape especially the rear end shape becomes more numerous. In addition to the three typical rear end shapes – notchback, fastback and squareback – some new concepts are derived from a mixture of those classic rear end shapes. For example an SUV-coupe like vehicle has a much higher trunk and a more raised trunk lid slope angle than a normal limousine or coupe. On some limousine models like the Porsche
Panamera Sport, the rear end shape is designed as a fastback. Its rear screen angle is smaller than a station wagon. Moreover, the rear underbody diffuser is often equipped to improve the vehicle road behavior.
Aerodynamic studies on the vehicle basic shape in the past decades were predominantly carried out in conventional wind tunnels with fixed ground and stationary wheels. With the ongoing development of wind tunnel testing techniques – e.g. moving belts, boundary layer suction systems and wheel rotation units – the flow field around a vehicle can be simulated much closer to reality. The optimization of the vehicle shape using a wind tunnel with ground simulation can be different from the optimization results in wind tunnel with fixed ground.
Previous investigations carried out by Wiedemann et al. have explained the physical mechanism of the ground simulation. They revealed its non-negligible influence on vehicle aerodynamics. Nevertheless, only few investigations exist that vary the vehicle rear end shape systematically and consider the influence of the chosen ground simulation technique. Thus, the aim of the present research is to provide a complement to the historic investigations on the vehicle rear end shape with respect to a more sophisticated ground simulation.

Mitglieder-Login