Air Pressure Pulse Developing Regularity of High-speed Trains Crossing in Open Air

The air pressure pulse produced by two high-speed trains crossing will cause unfavorable effects on running trains and railways and give rise to strength problem,running stability problem,abrasion problem between wheels and tracks and operation safety problem.Railway engineers all over the world have wanted to understand the developing regularity of the air pressure pulse since high-speed trains operation from 1960s,yet there is no unanimous opinion up to now.Based on computational fluid dynamics equations and finite volume numerical method,the processes of trains crossing are simulated.About 100 operating cases include 6 track distances,from 4.26 m to 5.26 m,and 38 speeds of trains crossing,from zero to 500 km/h,are calculated.A developing regularity of the air pressure pulse amplitude related with track distance and speeds of two trains crossing each other is obtained.At the same time,the developing regularities of the positive air pulse amplitude and the negative air pulse amplitude related with the same factors are also obtained.The formula for calculating the air pressure pulse amplitude provides reference for design of high-speed trains and construction of high-speed railways.