Flow analysis around a rotating wheel

Abstract: Wheel’s contribution to vehicle aerodynamic drag is around 25%. Reducing this amount is of great interest to diminish fuel consumption and CO2 emissions. The knowledge of vortex structures around the wheel is therefore necessary to understand the physical mechanisms of vortex dynamics and to develop a strategy for flow control. Particle Image Velocimetry (PIV) and aerodynamic torque measurements have been carried out in a wind tunnel in order to analyze the flow around a rotating wheel located inside a wheel arch. This study has been conducted in collaboration with RENAULT Research Department, Aero Concept Engineering (ACE) and ISAT (Institut Supérieur de l’Automobile et des Transports). Detailed flow-field measurements of a 40 percent full-scale bluff body have been obtained using two-dimensional PIV in the wind tunnel facility of ACE in Magny-Cours, France. Drag coefficient data have also been acquired using balance measurements for several wheel arch volume parameters. A global increase in drag has been shown with wheel arch volume growth. Longitudinal vortex structures such as “jetting ” have also been visualized using PIV. Wake characterization for three wheel arch volumes has been obtained. Flow structure differences between stationary and rotating wheel have also been observed for one wheel arch volume configuration