Abstract: Air has become one of the key constraints for the further acceleration of high-speed trains.In order to develop the next generation of higher-speed transportation systems, an innovative transportation system concept combining low-vacuum pipes and ultra-high-speed trains has been proposed and developed. In this paper, a two-dimensional calculation model of the tube train is established, and the shock wave characteristics of the supersonic train running in tube are analyzed based on the verified grid and turbulence model. It is concluded that when the supersonic train is running, the shock wave in front of the train forms a congested section forward in the form of a normal shock wave. The position of the normal shock wave moves forward with the running time, and the position of the pressure surge moves forward synchronously, but the pressure rise ratio before and after the shock wave is basically unchanged. The running time and the running Mach number affect the length of the congested section. The shock wave will undergo multiple Mach reflections between the tube and the train body and in the wake area to form a shock wave train. As the running time increases, the shock wave between the tube and train body weakens, and the intensity of the shock wave and reflected shock wave at the rear of the train is strengthened.

Key words: supersonic speed, tube train, shock wave characteristic, normal shock wave, shock wave reflection