Compressible effects of a supersonic evacuated tube maglev train at various Mach numbers

Abstract

Evacuated tube maglev train (ETMT) system aims to advance ultra-high-speed transportation, featuring unique high-speed flow phenomena and complex shockwave dynamics in low-pressure environments that demand further exploration. This paper examines the flow structures and aerodynamic loads of the ETMT over a range of Mach numbers from 0.8 to 2.0. Leveraging a compressible, density-based solver based on the Advection Upstream Splitting Method, extensive numerical simulations of the ETMT were conducted across transonic and supersonic regimes, revealing diverse aerodynamic characteristics under varying operational conditions. The research delineates how aerodynamic properties distinctively shift with operating Mach numbers. In supersonic conditions, distinct shockwave effects emerge prominently, and as the train's velocity escalates, there is a consistent reduction in overall drag and lift coefficients, resulting in a net reduction of 32% in the total train drag coefficient (a most economical Mach number of 1.8) and the lift diminished by 38%. However, notable disparities exist in the drag and lift coefficients among different train sections. These insights are instrumental in understanding the aerodynamic behavior of tube trains at ultra-high speeds and serve as a crucial guide for the train's exterior design.