Unsteady Loads on Ground Vehicles: Testing with Real-Life Conditions

Abstract

Testing of the aerodynamics of ground vehicles is mostly performed with steady wind conditions. However, real life is not steady. To which extent are the loads like crosswind forces and drag on trains and cars affected by gusts und turbulent flow conditions? To give an answer to this question, the incoming flow of vehicles in operating conditions was investigated using a car equipped with measurement equipment on a test track in various driving scenarios. The results were analysed regarding the unsteady flow parameters like degree of turbulence and length of the dominant flow structures. To test the influence of these flow parameters on the loads of trains and cars, a wind tunnel was kitted up with a wing system with movable flaps which acts as gust generator. Using this gust generator the unsteady loads on trains and cars are investigated depending on the flow parameters and are presented here.