Influence of Nose-slenderness Ratio on Air Pressure Pulse of High-speed Trains Passing Each Other

Abstract

The strength of side windows, the stability of train operation, and the comfort of passengers will be affected by air pressure fluctuations when the high-speed train meets. Based on the three-dimensional, compressible, and unsteady two-equation turbulence model, the moving grid technique and the finite volume method were applied to simulate the high-speed train meeting in the open air with nose-slenderness ratios of λL1=3.43, λL2=5.01, λL3=6.59 respectively, and the pressure curves of seven monitoring points near the side window of the train are obtained. The results show that when trains with different slenderness ratios meet at the same speed, the train with a smaller nose-slenderness ratio will suffer greater aerodynamic impact. When the three trains with different slenderness ratios meet at the same speed with the same observing train, the train with a larger nose-slenderness ratio has a smaller amplitude of the head pressure wave and the tail pressure wave, while the train with a smaller nose-slenderness ratio has a larger amplitude of the two kinds of the pressure wave. The reduction rate range of head pressure wave amplitude is 16.0-43.3% and that of the tail one is 13.5-32.1%. It can be seen that the air pressure pulse amplitude of trains crossing in the open air can be reduced by increasing the nose-slenderness ratio of the train.

Keywords

• train crossing
• numerical simulation
• high-speed train
• aerodynamic performance