Aerodynamic Wheel Force Measurements on a Detailed Scale-Model Car – Possibilities and Challenges

The energy consumption of the road-going vehicles must be reduced as much as possible, and minimizing the aerodynamic drag constitutes one significant part of this on-going work. It has been shown that ground simulation is essential when analysing the flow around the car, since the under-body flow region generates more than half the total aerodynamic drag. The cooling flows and the complex wheel-housing flow-fields are key areas in this context; the latter in particular. Hence, in this paper, forces acting on the rotating wheel are outlined and comparisons of different methods for determining these forces are given. A specific idea of system solution, to be implemented in the wind-tunnel at Chalmers University of Technology is also presented.