Numerical Study on the Aerodynamics of the Evacuated Tube Transportation System from Subsonic to Supersonic

• Published in: Energies (Basel) 2022-05, Vol.15 (9), p.3098, Article 3098
• Main Authors: Zhou, Zhiwei, Xia, Chao, Shan, Xizhuang, Yang, Zhigang
• Format: Article
• Language: English
• Subjects: Aerodynamic characteristics; aerodynamic drag; Aerodynamics; Compressed air; Drag coefficients; Drag reduction; Elastic waves; evacuated tube transportation; Evacuation systems; Flow velocity; Low pressure; Musk, Elon; numerical simulation; Open systems; Pressure; Reynolds averaged Navier-Stokes method; shock wave; Simulation; Subsonic aircraft; supersonic speed; Topology; Trains; Transportation systems; Turbulent flow
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en15093098

In this study, the aerodynamic characteristics of the three-dimensional evacuated tube transportation (ETT) system based on the Reynolds-averaged Navier–Stokes κ−ω shear-stress transport turbulent model were investigated. The effects of two key parameters on the drag and flow topology of the ETT system, namely the travelling speed and ambient pressure in the tube, were studied. Compared with trains in the atmospheric environment without the tube (i.e., the open system), the ETT system shows considerable drag reduction with suitable operating parameters in the tube, particularly at a higher travelling speed range. The drag varying with the speed from subsonic to supersonic, shows various change trends at different speeds because of their distinct flow structures. The higher pressure in front of train head was observed to be reduced by choking, and a low pressure in the wake by expansion waves led to rapid increase in the drag and drag coefficient. The relationship between the drag and operating pressure was observed to be approximately linear for both the subsonic and supersonic speeds.