Abstract: In order to research the aerodynamic performances of a train subjected to different types of wind, the aerodynamic performances of the train under the uniform wind and exponential wind are numerically simulated, respectively. The train aerodynamic model is established for the numerical simulation, and grid independence is made for selecting the appropriate computing grid. The effect of different types of crosswind on the incoming flow of the windward of the train, the aerodynamic forces of the train, pressure distribution on the train and flow field around the train are investigated. Comparing to the exponential wind, the incoming flow velocity of the windward of the train subjected to the uniform wind is larger, and the side force and overturning moment of the train are about 18% larger than those of the train subjected to the uniform wind. By comparing the differences in the aerodynamic performances of the train running on the flat ground and embankment, it is found that the aerodynamic performance of the train is worse when the train is running on the leeward side of the embankment. Results show that there are considerable differences in aerodynamic performances of the train subjected to the uniform wind and exponential wind. The lateral force and overturning moment of the head car are largest and the running safety is the worst among all cars. The aerodynamic forces of the train running on the leeward side of the embankment are larger than those of the train running on the flat ground.

Key words: exponential wind, flow field analysis, train aerodynamics, uniform wind