Numerical Simulation and Experimental Research of Influence of Underbody Structure on Aerodynamic Characteristics

In order to reduce the aerodynamic drag and obtain the optimal underbody airflow shape,the CFD method was applied to study the airflow Characteristics of underbody and analyze the airflow principles of underbody and wake.The result shows that the influence of underbody structure is notable on airflow characteristics of underbody and wake characteristics.Underbody structure is one of the critical components to aerodynamic characteristics of car,which makes the drag coefficient increase 0.0523 and the lift coefficient increase 0.1495 as well.Further analysis indicates that the largest reduction of drag coefficient is 0.0136 because of the optimal velocity of exhaust.The simulation results agree well with the test data in the wind tunnel and PIV test date,which indicates that numerical simulation for automotive aerodynamics characteristics is feasible.Analysis of the results can give a beneficial basis for underbody designing.