Computational and Experimental Evaluation of a Pad Correction for a Wind Tunnel Balance Equipped for Rotating Wheels

In a wind tunnel with simulation of the rotating wheels the measured lift is affected by pressure forces acting on the surface of the mini belts used to drive the wheels. The belt surface is part of the weighted model and the pressure forces therefore have to be subtracted to obtain the correct lift result. For stationary wheels this pad correction can be determined experimentally, but this is not possible for rotating wheels. Therefore a computational investigation was carried out using the CFD code FLUENT. The calculation is first verified for the case of stationary wheels and is then extended to rotating wheel case. The influence of a number of parameters as pad dimensions, position on the pad, vehicle shape and tire dimensions is studied. An approximate correction both for rotating and stationary wheels is given for the wind tunnel in question.

The investigation described in the paper is a good example for the necessary integration between state of the art test techniques and advanced CFD calculations.