挟沙强横风环境下高速列车的冲蚀性能

Erosion Performance of High Speed Train under Strong Cross Wind with Sand

在中国的西北地区,高速列车需要在挟沙强横风环境下行驶,风沙的冲蚀会对列车的行车安全造成隐患。为了研究风沙环境下高速列车的冲蚀效应,基于空气动力学理论,使用Navier-Stokes方程、标准k-ε湍流模型(k为湍动能,ε为耗散率)对气流进行连续化假设,应用离散相模型(discrete phase model,DPM)对沙粒粒子进行离散化处理。数值模拟了不同风速、不同沙粒粒子直径、不同浓度下的高速列车冲蚀效应,采用欧拉-拉格朗日方法进行求解计算。结果表明:速度越大,反射后的粒子距离列车表面越远,偏航角越大,列车附近的粒子运动越无规则;当速度不变时,列车车头处的冲蚀率随着粒子直径的增大而增大;当粒子直径不变时,冲蚀率随着粒子浓度的增大而增大,随着速度的增大呈现先减小后增大的趋势,且最大冲蚀率是最小冲蚀率的2.8倍。

In northwest China,high-speed trains need to run in the environment of strong cross wind with sand.The erosion of wind and sand causes hidden dangers to the train operation safety,In order to study the erosion effect of high-speed train in the wind and sand environment,based on the aerodynamics theory,the Navier-Stokes equation and the standard k-εturbulence model(k is turbulent kinetic energy,εis dissipation rate)were used to continuous the air flow,and the discrete phase model(DPM)was used to discrete the sand particles.The erosion effect of high-speed train under different wind speed and sand particle diameter and concentration was simulated.The Euler Lagrange method was used to solve the problem.The results show that the farther the reflected particles are from the train surface with increase of velocity and the more irregular the movement of particles near the train is with the increase of yaw angle.When the velocity is constant,the erosion rate of the train head increases with the increase of diameter.When the diameter of particles is constant,the erosion rate increases with increase of concentration,but with increase of velocity,the erosion rate decreases first and then increases,the maximum erosion rate is 2.8 times of the minimum erosion rate.