An Experimental Investigation of Wheel-Well Flows

The addition of wheel-wells and wheels to a basic automotive body results in significant changes to the drag and lift produced by the vehicle Wind tunnel tests were conducted with a generic automotive body shape that included wheel-wells that could be varied in radius, or height, and depth The range of depths and radii encompassed wheel to wheel-well relationships for a wide range of vehicle types All tests were performed using a moving ground plane and rotating wheels for proper ground and wheel simulation respectively The wheels were mounted independent of the body by cantilever struts attached to the wind tunnel walls to allow the forces on the body and wheels to be measured independently Additionally, surface oil flow visualization, tufts and surface mean pressure measurements were employed to identify the aerodynamic mechanisms responsible for the forces measured.

The addition of wheels and wheel-wells increased both lift and drag It was found that the vehicle drag increased primarily as wheel-well radius increased and vehicle upward lift initially decreased to a minimum and subsequently increased with increasing wheel-well depth The major proportion of the lift increase due to the addition of wheels and wheel-wells was produced by the body The increase in drag and changes in lift were primarily due to the interaction of the interference produced by the wheel and wheel-well with the basic body flow.