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

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, as demonstrated in Figure 1, 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.