Study on effect of train's shape on aerodynamic performance by moving zone
LUAN Fei-zhou， CHEN Li-hua
（Institute of Aeronautics and Astronautics， Zhejiang University， Hangzhou 310027， China）

Abstract：  In order to solve the problems of the relative movement about the train and tunnel，the moving zone was investigated. The unsteady flow of train passing through the tunnel was studied by computation of the compressible Navier-stockes equations and  equations based on the physical model. The effects of the head-shape on the vortex around tail of train and the pressure on train body were studied，and the effects of the length of the train towards the friction drag and pressure drag of the train were researched. The head-shape and train's length were evaluated based on the results. The results indicate that the higher the streamline shape is，the smaller the aerodynamic drag is，and the lower the vortex around the tail of the train is. The length of the train has little effect on the pressure drag，but has great influence on the friction drag. The conclusions based on the research could provide a theoretical basis about the design of the head-shape of the train. Meanwhile，it could provide a reference for the design of the length of the train and the drag reduction.
Key words： high speed train；unsteady flow；vortex around tail of train；computer simulation；aerodynamic drag