高速列车侧风效应的数值模拟

在侧风作用下，高速列车的空气动力学性能发生显著改变．基于三维定常可压缩流动的N-S方程，采用SST k-ω两方程湍流模型和有限体积法，对某型高速列车以350km／h的速度在25m／s侧风环境中运行的流场结构和气动力进行了数值模拟计算，分析了不同风向角的侧风对列车全车，以及受电弓、转向架和风挡等局部区域的作用．结果表明：在侧风作用下，列车的周围包括转向架处均产生复杂的涡流，压力分布十分复杂，转向架对流场的影响不容忽视；随着风向角（0～90°）的增大，侧向力系数及倾覆力矩系数也增大，列车倾覆及脱轨的风险性增加，且头车的倾覆力矩系数远大于中间车和尾车的倾覆力矩系数，应注重对头车的气动性能研究．

Numerical Study on the Crosswind Effects of High-Speed Train

The aerodynamic performance of high-speed train will significant change under the action of the side wind. Flow around a certain high-speed train with 350 km/h under the influence of a crosswind with 25 m/s has been studied by numerical technique. To compute the different flow structures numerically, the three-dimensional Reynolds-averaged Navier-Stokes equations, combined with the standard SST k-ω turbulence model, were solved on a multi-block structured grid using a finite volume technique. The impact of different wind direction angle of the side wind on the whole train, pantograph, bogies and inter-car gaps was analysed. The resulting flow fields show that complex vortex and pressure distribution generate around the train and bogies, so the bogies can not be ignored. The Lateral force coefficient and overturning moment coefficients increase with the increasing wind direction angle, and the risk of the train overturned and derailment increase too. Moreover, the overturning moment coefficients of the head train is much larger than the middle and the tail train, so, the research of the aerodynamic performance of the head train should be attended.