Effect of Air Pressure on Aerodynamic Characteristics of the HTS Maglev Running in a Tube

The high-temperature superconducting maglev-evacuated tube transport (HTS Maglev-ETT) is a green, energy-saving, and high-speed future transit mode. The initial tube pressure is a vital parameter of the ETT system. To investigate the impact of the initial tube pressure on the aerodynamic characteristics of the HTS maglev, a two-dimensional scaled simulation model of 1:10 was established. The aerodynamic drag of the train and the shock wave phenomenon in the tube under different initial tube pressures were studied. The study found that the shock wave formed in the tube contains oblique shock wave and normal shock wave. There is a linear relationship between the range of the shock wave and the initial tube pressure. The range of the shock wave and aerodynamic drag increase with the increases of initial tube pressure. Additionally, the pressure drag plays a dominant role in the total drag. By lowering the pressure in the tube, the pressure difference between the front and rear of the train was reduced, thus reducing the aerodynamic drag.