Calculation method of cross wind security domain for high-speed train

Based on parameter transmission, solution to control and dynamic mesh techniques, the cross wind fluid dynamics model and the multi-body system dynamics model of high-speed train were established.By collaboratively simulating the external flow field and system response of train, the stable attitudes and aerodynamic loads under different cross wind environments were obtained.The running safety indexes were studied, the critical speeds of running safety under different cross wind environments were analyzed, and the security domain was defined.Calculation result indicates that with the increases of train speed and cross wind strength, the transfinite phenomena of wheel unloading rate, derailment coefficient and lateral wheelset force appear successively.While train speed is less than 300 km·h^-1, all wheelsets of leading vehicle almost have upwind migration.While train speed is 300 km·h^-1 and cross wind speed is 30 m·s^-1, and train speed is 350 km·h^-1 and cross wind speed is more than 25 m·s^-1, the first and second wheelsets have downwind migration, the third and fourth wheelsets have upwind migration.The higher train speed is, the lower the cross wind resistance ability is, and the sensitivity of train critical speed on cross wind strength will increase.