Analysis on Shock Wave Characteristics of Two-Dimensional Rendezvous Train in Tube

The train running in the low vacuum tube can greatly reduce the resistance, but it also faces the problem of the shock wave effect. We establish a two-dimensional tube simulation model. The compressible unsteady SST k-ω turbulence model combined with sliding mesh technology was used to study the evolution of shock waves in the tube under different initial intersection distance, velocity and time. The results show that when the two trains are far away from each other, the congestion section in front of the train moves forward, and the congestion length increases linearly with time. When the normal shock waves disturb each other, the absolute value of drag/pressure increases sharply. When the two locomotives meet, the absolute value of resistance/pressure increases sharply again to the maximum value and decreases sharply to a relatively stable state with the operation of the train. During the intersection, the resistance/pressure decreases first and then increases along the tail direction. Shock wave and expansion wave cross each other in the rear area; the wave system is more complex, and the intensity of the shock wave reflection is weakened along the rear direction. With the increase of the intersection distance, the resistance/pressure of the train running in short and medium tunnels (<1500 m) changes dramatically. Long tunnel (>1500 m) resistance/pressure change amplitude is small. As the speed increases, the length of the congestion section in front of the train is shortened, the resistance/pressure absolute value increases, the length of the rear shock train increases, and the intensity decreases.