单列高速列车通过隧道空气阻力特性数值模拟研究

Numerical simulation of aerodynamic drag of single high-speed train passing through a tunnel

针对高速列车空气阻力直接影响列车最高运行速度,采用真实外形的8编组国内某型动车组,建立单车通过隧道的数值计算模型,并对隧道空气阻力的形成机理及其随时间的变化特性、列车表面压力与阻力两者变化间的关系、列车各部件阻力的分布特性进行分析;对比隧道通过时整车阻力的最大值、最小值和明线整车的阻力值。研究结果表明:列车通过隧道时,隧道内压缩波和膨胀波对列车阻力有直接影响,列车空气阻力呈现准周期性波动,其中压差阻力的波动幅度比摩擦阻力的波动幅度大;压差阻力和摩擦阻力所占的比例随时间而变化;列车空气阻力的最大值和最小值分别为明线的1.96倍和0.89倍。列车明线稳定运行时,压差阻力和摩擦阻力分别占列车空气阻力的61.7和38.3%。列车通过隧道过程中,列车各部件阻力分布特性随时间而变化。

Based on the aerodynamic drag directly affects the maximum running speed of high-speed train,this paper established the numerical calculation model for single train passing through the tunnel with the real configuration of a domestic EMU with eight carriages.The formation mechanism and variation characteristics of the tunnel aerodynamic drag over time,the relationship between the changes of the car body surface pressure and the drag,the distribution characteristics of the drag of individual parts of the train were analyzed at different times of the train when passing through the tunnel.The maximum and minimum of the drag values for going through the tunnel were compared with the drag of the open air condition.Results indicate the compression and expansion waves directly affected on the drag,the drag showing quasi-periodic fluctuations over time of the whole train,the fluctuation range of the pressure drag is larger than the friction drag,the possession ration of pressure drag and friction drag are changed over time when the train passing through the tunnel.The maximum value and minimum value of total drag when the train passing through the tunnel are 1.96 times and 0.89 times of that in the open air.When the train is running in the open air,the pressure drag and frictional drag accounted for 61.7%and 38.3%respectively of the total aerodynamic drag.The distribution characteristics of the drag of individual parts of the train are changed over time.