An Investigation into the Flow-Field About an Exposed Racing Wheel

Detailed flow-field measurements in the wake of a 40 percent full-scale exposed wheel have been obtained using particle image velocimetry (PIV). Additional data have been acquired in the form of surface static pressure measurements acquired using the Durham University radio telemetry system. The results presented in this paper compare and contrast, both quantitatively and qualitatively, the physical differences that exist with respect to the flow structures of rotating and non-rotating wheels. Some of the ‘special’ features of the flow-field postulated by Fackrell, such as the ‘jetting’ phenomenon, have been revisited, examined and revised based on the surface static pressure and PIV data presented in this paper. The experimental observation of a flow mechanism is presented in terms of the rear jetting after the line of contact, and the effects of this have been considered and analyzed.