Study On Capsizing Stability Of Emu In Cross-wind

The aerodynamics of the high-speed EMU could be deteriorated in cross-wind, even make the train capsized. Especially in special windy circumstances such as large bridges and high embankments, the bypassing flow field of EMU changes, and the aerodynamic force increases sharply, therefore, the possibility of capsizing enhances. So, it is significantly important to ensure the security of travelling by researching on the cross-wind stability of EMU in special windy environment.Based on the principle of CFD (computational fluid dynamics), the operation conditions of EMU on bridge, embankment, cut and flat in cross-wind were simulated numerically by FLUENT. The aerodynamic force, moment and the distribution law of the external flow field on different conditions were obtained. The equation of train stability was derived with the theory of moment balance from the view of dynmnics. An analysis system about capsizing stability was developed by MATLAB, which consists of the following functions, inputting parameter, analyzing aerodynamic forces, calculating critical wind speed, critical vehicle speed, comparing various conditions and so on. By using this analysis system, the influence on capsizing stability of EMU was studied from the different factors, such as weight of the vehicle, height of the barycentre, lateral vibration acceleration, curve radius, curve superelevation. And then the methods of improving the stability of EMU were given.The study results supply the great the referential and practical value for the security of EMU in cross-wind.