研究目的:冰雪飞溅是严寒地区高速铁路有砟轨道面临的重要问题之一,列车结构和道床断面形式都是其重要影响因素.本文基于k-εRealizable湍流模型,采用滑移网格技术,建立CRH3型高速列车-有砟道床模型,对列车绕流特性和道床空气动力学特性进行研究,揭示冰雪飞溅机理,以期为优化道床断面和防治冰雪灾害提供理论基础.研究结论:(1)车头、车尾和转向架区域,风速和风压出现大幅度波动,冰雪飞溅几率较高;(2)道床中心风压较大,风速较高,冰雪块极易发生飞溅现象,道床表面风压由内向外递减,轨枕槽内易出现冰雪块移动和堆积;(3)列车速度是影响冰雪飞溅的关键因素,随着车速增加,风压值随之变大,列车速度在250 km/h以上时,车速每增加100 km/h,风压峰值增加约1倍,冰雪飞溅几率明显增加;(4)风压随着砟肩堆高的增大而增大,在列车速度为350 km/h条件下,砟肩堆高由0 mm到150 mm,负压峰值增幅达9.0％,因此在保证道床横向阻力基础上宜降低砟肩堆高;(5)本研究结论可为冰雪飞溅防治提供工程依据及指导作用.%Research purposes:The problem of snow flight obsesses high speed railway in cold region,where train structure and ballast bed cross section are important factors.In the paper,the k-epsilon Realizable viscous model is adopted together with sliding mesh technique,and CRH3 train-ballast bed numerical model is used to investigate aerodynamic effects,which reveals the mechanism of snow flight and provides theoretical basis for optimizing ballast bed cross section and preventing snow flight.Research conclusions:(1) Train head,tail and bogie area result in large fluctuation of wind pressure and speed,where the probability of snow flight is high.(2) There is large wind pressure and speed in the center of ballast bed,and snow blocks are easy to move and splash;the value of wind pressure decreases from center to side,and snow blocks are prone to move and cumulate in crib.(3) The key aerodynamic factor of snow flight is train speed.The value and fluctuation of wind pressure become larger with train speed increasing.When the train speed is above 250 km/h and increased by 100 km/h,the peak value of wind pressure is double.(4) The wind pressure increases with shoulder height,whose height of the shoulder ballast is from 0 mm to 150 mm at train speed 350 km/h,and the peak value of negative pressure increases by 9.0％.With lateral resistance value reach requirements,the shoulder height should be reduced.(5) The research conclusions can provide basis and reference for prevention and control of snow flight.
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