An investigation of the wind-induced rolling moment on a commercial vehicle in the atmospheric boundary layer

Full-scale measurements were undertaken on a commercial vehicle in the atmospheric boundary layer in order to establish the variation in rolling moment coefficient with yaw angle. Both moving and stationary experiments were undertaken and it is shown that for the purposes of the current analysis it is sufficient to neglect the motion of the vehicle. Two approaches were used to determine the rolling moment on a stationary vehicle: direct measurement using load cells, and indirect measurement obtained from the integration of vehicle surface pressures. Results obtained using both methods are shown to agree within acceptable limits. The aerodynamic admittance of the rolling moment was also investigated and is shown to be a function of the yaw angle. Furthermore, the importance of the lateral velocity component on the aerodynamic admittance is illustrated. Finally, the peak values of the rolling moments are evaluated and are found to illustrate non-Gaussian behaviour.