Aerodynamic design of a subsonic evacuated tube train system

The so-called Evacuated Tube Train (ETT) is currently being proposed as a high-speed transportation system potentially competitive with airplane transportation. Aerodynamic resistance is one of the most crucial factors for the successful design of an ETT. In the present work, a three-dimensional concept ETT model has been elaborated. The aerodynamic characteristics of the subsonic ETT have been numerically simulated under different conditions. The train's running speed varies from 600 km/h up to 1200 km/h, and the blockage ratio is in the range between 0.1 and 0.3. As the blocking ratio and running speed increase, the resistance of the head car increases greatly, while the resistance of the middle car changes slightly. The aerodynamic resistance of the tail car is affected by the shock wave emerging in the wake flow. Two different design criteria for the maximum allowed aerodynamic resistance are proposed for aerodynamic parameter matching. With an increase in the blockage ratio and running speed, the atmospheric pressure in the tube should be decreased to achieve a balance. © 2020, Tech Science Press.