Some Salient Features Of The Time-Averaged Ground Vehicle Wake 840300
For a basic ground vehicle type of bluff body, the time averaged wake structure is analysed. At a model length based Reynolds number of 4.29 million, detailed pressure measurements, wake survey and force measurements were done in a wind tunnel. Some flow visualisation results were also obtained. Geometric parameter varied was base slant angle. A drag breakdown revealed that almost 85 % of body drag is pressure drag. Most of this drag is generated at the rear end.
Wake flow exhibits a triple deck system of horseshoe vortices. Strength, existence and merging of these vortices depend upon the base slant angle.
Characteristic features of the wake flow for the low drag and high drag configurations is described. Relevance of these phenomena to real ground vehicle flow is addressed.