Wind tunnel tests for mean wind loads on road vehicles

• Wind tunnel tests were carried out on various vehicle models.
• Results were compared with other wind tunnel tests results.
• Flow conditions did have effects on the variation of wind loads.
• The vehicle type significantly affect aerodynamic moment coefficients.

Evaluation of the safety and performance of road vehicles in windy conditions requires accurate descriptions of wind loads on vehicles. However, the research in this area has been far from comprehensive. In the present study, wind tunnel tests were carried out on various vehicle models under different flow conditions, including smooth flow, turbulent flow, and boundary layer flow. The lift, drag, and side forces, and the pitching, rolling, and yawing moments for these vehicle models were measured and analyzed to interpret the effects of flow conditions on these forces. The results were also compared with other wind tunnel tests results published in the literature. The experimental results reveal that the flow conditions did have effects on the variation of wind loads; the smooth flow case is a conservative estimation in general. The height of the center of gravity of the vehicle will significantly affect the results of the aerodynamic moment coefficients, which causes the significant difference between different studies. The results under the boundary layer flow also provide a good reference guide for the context of applications such as stability problem of still vehicles under extreme wind events.