Effect of cross winds on high-speed trains: development of a new experimental methodology

Optimising the running performance and increasing the stability and comfort of high-speed trains require the knowledge of aerodynamic behaviours with cross winds. The rolling moment and the side force are determined by the leading vehicle design, especially by the head shape of the first car. In this paper, a new methodology based on pressure field measurements has been developed in order to know the local and instantaneous aerodynamic loads. Complementary calculations can also give the density of aerodynamic forces along each vehicle. Therefore, thanks to this method, the loads associated to each part of the vehicle can be defined. Mean aerodynamic forces measured by a classical dynamometer balance fit the pressure measurements. The method presented in this paper provides a reliable way to assess the aerodynamic forces due to side wind, source of discomfort and risk of overturning.