Study on the influence of atmospheric environment change on the temperature field of vacuum tube

The temperature distribution in the vacuum tube directly affects the aerodynamic performance and operation safety of the maglev train. It is of great significance to study the influence of the atmospheric environment effect for the construction of the vacuum tube train transportation system in the future. The parameters of the atmospheric environment such as the solar radiation intensity, air humidity, temperature and wind speed in each season are obtained by collecting meteorological data of Chengdu in recent five years. The numerical calculation method of the radiation heat transfer from the vacuum tube is established. The DO (Discrete Ordinate) radiation model was used to study the influence of solar radiation on the air flow in the vacuum tube, and the temperature distribution and variation rule of the air flow in the tube under conditions of different seasons and different vacuum degrees were obtained. The results show that the air in the tube has a stable temperature rise under the influence of solar radiation. With the same vacuum degree, the temperature in the vacuum tube is the highest in summer and the lowest in winter. With the gradual decrease of the vacuum degree, the temperature of the air flow in the tube increases gradually in each season. When the vacuum degree is 0.1 atm (～10.1 kPa), the air temperature in the vacuum tube increases by 56.60 K in summer.