覆雪准则参数改进的高速列车转向架覆雪模拟

采用Realizable k-ω湍流模型，耦合离散相模型(DPM)，对高速列车运行时的车底覆雪问题开展模拟研究. 模拟中，考虑流场作用与颗粒-壁面碰撞特征2个方面，建立基于壁面阈值摩擦速度与颗粒-壁面捕捉角的壁面覆雪判别准则. 选用Paradot开展的简单几何体覆雪试验作为原型，通过控制变量分析，对准则参数设置的合理性进行讨论. 与原型覆雪的结果对比表明，以往研究中对覆雪准则相关参数的取值偏小，建议改进2个判别参数，分别为1.0 m/s与60°. 利用改进参数的准则，对我国现有运营某型号高速列车运行时的转向架覆雪进行模拟评估. 结果表明，转向架易出现覆雪的区域主要位于部件背风侧壁面及连接角落，尤其是中部构架横梁与齿轮减速箱，后转向架覆雪分布区域更分散.

Simulation of snow accumulation on high-speed train bogies based on snow-wall bonding criteria validation

A simulation study of analyzing the snow accumulation on the bogie regions of a high-speed train was conducted based on the Realizable k-ω turbulence model coupling with the discrete phase model (DPM). A series of snow-wall bonding criteria, including surface threshold friction velocity and capture angle, were proposed by considering the interactions and collisions between flow and particles. The rationality of the parameter settings was discussed by using control variable parameter analyses based on the prototype test provided by Paradot. The simulation results were compared with the prototype test. The parameter settings adapted in the previous studies for the snow-wall bonding might be relevantly low. The relative values in the criteria are 1.0 m/s and 60°, respectively. Then the validated parameter settings were used, and the snow accumulation estimations on the bogie regions of a high-speed train in China were conducted. Results show that snow accumulations are mainly located on the leeward side (surface) of each bogie component and connecting corners, especially the frame beam and the gear reduction box. The snow-covering areas of the rear bogie are more dispersed.