Influence of Wind Tunnel Floor Configuration and Ground Height on the Aerodynamic Behavior of a DrivAer Model

Aerodynamics plays an important role in fuel economy and vehicle stability, aiming to deliver full performance while moving on the road. To develop the aerodynamics of vehicles at the early stages of a project, Computational Fluid Dynamics (CFD) simulations and wind tunnel test are the main tools used by automakers to help achieve the desired aerodynamic performance. One of the most relevant factors of CFD and wind tunnel test is how the floor under the vehicle is represented, which may lead to different aerodynamic behaviors. This work aims to investigate the effect of two types of floor configuration on a generic vehicle, with open geometry using CFD simulations. The DrivAer model has been widely studied both numerically and experimentally and provides an interesting source of comparison for 5-belt and static floor configurations, proposed by the study. In addition to the floor configuration analysis, the study also presents a comparison of ground heights for the previous cases. Results are presented comparing the drag coefficient of the proposals, pressure and turbulent wake results to illustrate the differences in terms of flow behavior when changing the floor configuration and when changing the ground height.