Large Eddy Simulation Of The Vortices Interference Mechanism Between The Windshield Wake And Coherent Structure Around The High-speed Train

Since the opening of the Railway from Lanzhou to Xin Jiang,there have been a number of accidents in which trains were blown over by high winds,according to preliminary statistics,as of the beginning of this century,a total of several strong winds in the country caused the train to break down and fall accidents,seriously damage the safety of passengers’ lives and property,causing major economic losses to the country.In order to prevent the harm caused by strong winds to lines and trains,measures such as optimizing the choice of line scheme,setting up wind barrier,establishing a strong wind monitoring and early warning system,limiting train speed and so on have obtained good results according to foreign experience and research results.The aerodynamic characteristics of high-speed trains running behind the windshield are quite complex,and when the wind shield is installed,the impact on the train can be significantly reduced when the air flow passes through the bezel.Therefore,it is very important to study the interference of windshield tail vortex and high-speed train wall turbulence vortex,which is especially important for high-speed trains to travel safely behind the windscreen through the wind zone.In order to do better numerical simulations,it is necessary to remove the extra parts of the high-speed train model.On the basis of full demonstration,the grid is divided to determine the boundary conditions.Finally,the simulation is carried out according to the actual situation and the specific situation.After numerical calculation,the conclusions are:First of all,it is concluded that the side wind under the high-speed train in the wind wall after the operation of a long strip of vortex,when the side wind through the wind wall will be formed on both sides of the train at the same time negative pressure vortex,side wind will affect the train running when the formation of the symmetrical distribution of the vortex,so that the train tail vortex from the straight distribution along the direction of train operation to the oblique distribution of wind wall can reduce the impact of the train by the side wind.Second,the resistance coefficient of the vehicle in the case of sidewinds changes from0.27to0.65 in the case of no wind,and the lift coefficient changes from-0.0037 to-0.17.This indicates that the resistance of the train will increase significantly under the side wind conditions,which will lead to difficulty in travel,increased energy consumption,while the train’s lift coefficient indicates that the train is subject to large,increasing friction between the wheel pair and the rails,reducing the service life of the high-speed train.Finally,the interference mechanism of the wind retaining wall tail vortex and the highspeed train wall turbulence vortex is obtained,and the flow field characteristics of the windscreen wall and high-speed train are analyzed,the basic vortex structure of the windscreen tail vortex and the high-speed train wall turbulence is calculated,and the vortex interference mechanism of the windscreen tail vortex and high-speed train wall turbulence is obtained,which lays a solid foundation for the later research.