A fast equilibrium state approach to determine interaction between stochastic crosswinds and high-speed trains

Traditionally, the aerodynamics of high-speed trains and the corresponding dynamics arising from the vehicle-track interaction have tended to be considered in isolation. A fast equilibrium state approach to determine the interaction between stochastic crosswinds and a high-speed train is presented in this paper. The approach is achieved using the alternative iterations of aerodynamic and vehicle-track dynamics at different iteration intervals. First, an equilibrium state of the train is calculated using an alternative co-simulation in which both track irregularities and stochastic crosswinds are ignored. An aerodynamic admittance function is then introduced to calculate the unsteady aerodynamic loads of the train in stochastic crosswinds. Afterwards, the corresponding aerodynamic forces and moments are loaded to a vehicle-track coupling model, and dynamic responses of the vehicle-track coupling system are calculated. Finally, the crosswind stability of the train is evaluated. Both aerodynamics and vehicle-track dynamics of a high-speed train are numerically simulated under the condition that the crosswind velocity is 13.8 m/s and the train speed is 350 km/h. Results indicate that there is little difference in results calculated with the alternative co-simulation and fast equilibrium state approach. However, the fast equilibrium state approach is approximately 3 times faster than the alternative co-simulation.