Numerical Simulation of Flow Around Railway Vehicle in Turbulent Boundary Layer over Flat Terrain

Abstract

In order to investigate the running effects on aerodynamic characteristics of a railway vehicle under strong cross winds, the author performed Large-Eddy Simulation of flow around a simple running train model. To simulate the cross winds which affect a running train, the author used an inflow turbulence generation technique based on an unsteady flow simulation method in the frame of a train moving coordinate system. In the case where the train speeds are 10m/s, 5.8m/s, 1.8m/s and 0m/s and the wind speed is 10m/s in the direction perpendicular to the train running direction, the pressure coefficient distribution on the surface of the running train was obtained by numerical simulation and compared with that from experimental studies. The detailed flow fields around the running train were also presented. Based on the comparison between the running train simulation and stationary train simulation with the same relative wind angles to the train, the running effects on aerodynamic characteristics in the case of the simple train model were discussed.