Numerical study on the effect of temperature and scale ratio on aerodynamics of maglev trains moving dynamically in a vacuum transportation system

Abstract

The airflow around a vacuum tube maglev train operating at high speeds is complex. In addition, the effect of relevant parameters in such a transportation system on aerodynamic characteristics is crucial in the design and safety of the system. A three-dimensional (3D) vacuum tube train model is established based on a vacuum tube test platform for rail transit. The effects of the initial ambient temperature and scale ratio on the aerodynamic characteristics are analyzed during the whole operational process in this study. The results mainly focus on each process’s variations in the shock waves, choked flow, and drag. During acceleration, shock wave generation is advanced or delayed under different system parameters, which vary the aerodynamic drag. While the train runs at a constant speed, the time that a standard shock is generated and the length of the choked flow differ under the effects of the varying system parameters. In braking, the disappearance of shock waves and reflections of the expansion wave suddenly decreases the aerodynamic drag either earlier or later due to the varying system parameters.

Keywords

vacuum tube transportation / aerodynamics / shock wave / choked flow / drag

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