Research on Underbody Flattening of a Passenger Vehicle towards Aerodynamics Optimization

A CFD method for the full-scale external flow of a passenger vehicle is established. Based on the comparison between the simulation and wind tunnel test results, the reliability to use this model and method for the aerodynamic drag coefficient (Cd) and lift coefficient (Cl) prediction of the vehicle is verified. The trend of Cd and Cl for five models with different underbody flattening degree shows the significance of underbody flattening on the aerodynamic performance, with nearly 18% on the drag and over 30% on the lift coefficient optimization (paper)