Investigation of Skin Friction Topology on the AeroSUV Using GLOF Meter

In this study, the aerodynamics and skin flow field of a 1/5 scale SUV vehicle model called “AeroSUV” were experimentally investigated. The aerodynamics and skin flow field investigations were carried out in the wind tunnel at Hiroshima University with a Reynolds number ReL = 1.2×10^6, baseline yaw angle β = 0° and crosswind conditions β = 5°, 10° and 15° for two rear ends, Estateback and Fastback. The results provide aerodynamic information and detailed skin flow field information for a standard middle-class SUV vehicle with different rear ends, which is important for automotive design. By applying GLOF measurements to automotive aerodynamics, the skin friction topology was revealed in detail as skin flow field information that is useful for understanding the physics of the flow. The skin friction topology clearly shows the separation lines, reattachment lines, and focus points associated with the separation flow, longitudinal vortices and recirculation vortices of this vehicle model. Specifically, the skin friction topology of the AeroSUV Estateback and Fastback showed similar flow patterns in the engine hood, front window, roof, side body, and base, except for the rear window. Also, the flow pattern was similar to that of the baseline up to β = 5°, but at β = 10° and 15°, the flow pattern changed significantly for the rear window and the base. In particular, a characteristic counter-rotating vortex was observed in the flow pattern of the Estateback rear window at β = 15°. The interaction between the change in skin friction topology with yaw angle and aerodynamics was also discussed.