Theoretical and Numerical Studies on Shock Wave Detachment of Evacuated Tube Train

doi:10.3901/JME.2025.10.367

Abstract

Abstract: Research on aerodynamic characteristics of shock waves at the tail of evacuated tube train is essential for the design of evacuated tube transportation system. Based on the one-dimensional flow theory, the formula of the critical velocity of tail shock wave detachment is derived. Taking a high-speed maglev train as the research object, based on Sutherland equation and SST k-ω turbulence model, the aerodynamic characteristics of three-dimensional compressible subsonic and transonic evacuated tube train in speed of 600～1 200 km/h are numerically simulated. The results of the theoretical solution and numerical simulation are compared. The results show that the inverse pressure gradient of the attached tail shock wave causes the separation of the boundary layer on the train surface. The tail vortex moves to the rear of the train with the increase of train speed until the shock wave detached. The aerodynamic drag coefficient of the tail car increases, and then decreases with the incremental of the train speed. When the running speed is equal to the critical speed of the shock wave detachment, the drag coefficient is the largest and the magnitude of the pressure coefficient is the minimum. The one-dimensional flow theory predicts the critical velocity of shock wave detachment accurately, and the maximum error between theoretical derivation and numerical simulation is less than 7.63%.

Key words: evacuated tube train, one-dimensional flow, characteristics of field, aerodynamic drag, shock wave detachment

CLC Number:

U171

SONG Jiayuan, LI Tian, ZHANG Jiye. Theoretical and Numerical Studies on Shock Wave Detachment of Evacuated Tube Train[J]. Journal of Mechanical Engineering, 2025, 61(10): 367-375.

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