Pressure Wave Numerical Investigation For CRH5EMU Traveling Through Tunnels

When High-speed EMU go through the tunnels, it will produce a corresponding change in pressure and a series of aerodynamic effects. This effect will be significantly increased with the improvement of the train speed. When High-speed EMU go through the tunnels, the air pressure inside the tunnel will occur volatility within a very short time, forming transient pressure wave. The dynamic analysis using computational fluid dynamics software plays an important role in the implementation of the program of design.In this paper, we take simplified CRH5EMU as the model to produce250km/h single track tunnel computational model,250km/h and300km/h two-lane tunnel computational models.We take numerical analysis on its aerodynamic characteristics to get the detail information of train body surface pressure distribution, the tunnel wall pressure distribution and the tunnel velocity vector distribution by the post-processor visual display in graphical form.Numerical calculations show that the change of tunnel cross-sectional area will produce significantly aerodynamic characteristics change at the same speed. The maximum increment of nose pressure is up to40.6%at the same speed and different tunnel.At the same time, when the speed is up. the maximum increment of nose pressure is up to45.6%at the different speed and same tunnel.This paper provides a further research for domestic trains aerodynamic study and has a great significance to the safe operation of the high-speed trains.