Dynamic Effect of Heave and Pitch Motions on Simplified Automobile Model

Abstract

Dynamic effects on the pressure distributions around a sedan-type simplified automobile model were investigated by conducting forced oscillation tests in a wind tunnel. HEXA, an original 6-DOF parallel-link manipulator was used to impose heaving and pitching motions on the model and unsteady pressure distributions over the model surfaces were measured with the effects of the ground plate. The obtained results show that dynamic effects become prominent mainly on the front side of the model underfloor and change depending on the Strouhal number. The effects were mostly consistent to those predicted by the quasi-steady model, but the pressure ports near the far front side of the model showed different behaviors. It is suggested that these observations are related to the local separation regions found in surface-flow visualization tests.