Abstract: In order to achieve the co-simulation between train aerodynamics and vehicle-track coupling dynamics in crosswind, a fast and high-efficiency equilibrium state method is presented. Firstly, vehicle-track coupling dynamics responses to steady aerodynamic forces and train aerodynamics under steady attitude state are solved alternatively ignoring track irregularity. The equilibrium state is obtained by judging convergence criterion. The static forces of train in equilibrium state are loaded to the model of vehicle-track coupling dynamics and the responses of high-speed train are calculated. The fluid-structure dynamics of a high-speed train are simulated under the case that the velocity of crosswind is 13.8 m/s and running speed of train is 350 km/h. The differences in aerodynamic forces and safety indexes calculated with equilibrium state method, alternative co-simulation and off-line simulation are compared. The results show that there is little difference in results calculated with equilibrium state method and alternative co-simulation; however, the calculation efficiency of equilibrium state method is much higher than that of alternative co-simulation.

Key words: Aerodynamics, Crosswind, Equilibrium state, Fluid-structure interaction, High-speed train