高速列车转向架区域雪粒运动特性分析

Analysis of the motion characteristics of snow particles in the bogie region of a high-speed train

为了研究高速列车转向架区域的雪粒运动特性,建立了复杂外形转向架的气动计算模型,采用拉格朗日方法模拟雪粒在气流中的运动,研究了拖车转向架区域的雪粒运动特性及雪粒与壁面的撞击特性.研究结果表明:雪粒由两轮对后部向上翻转进入转向架区域,转向架区域下部雪粒浓度大、上部浓度小,底部气流挟带的雪粒只有小部分随上扬气流进入转向架区域;构架底部、轮对、刹车盘及制动夹钳下部等迎风区域为雪粒子集中碰撞部位,其雪粒撞击数量要比转向架其他区域高出1个数量级以上;列车运行速度为300 km/h时,转向架下部受来流直接冲击的部件表面雪粒撞击速率较大,雪粒撞击速率处于20~56 m/s范围,受转向架舱包裹的上部区域雪粒撞击速率小于20 m/s,转向架的顶部区域上表面平均粒子撞击速率小于2 m/s;列车高速运行时,雪粒集中撞击的区域绝大部分都具有较高的法向撞击速度.

In order to study the motion characteristics of snow particles in a high-speed train bogie region,the aerodynamic calculation model of a complex-shape bogie was established.The Lagrangian method was used to simulate the movement of snow particles in the airflow.The snow particle motion in the trailer bogie region and the impact characteristics of snow particles and walls were studied.The results show that the snow particles were turned upside down in the bogie region from the rear of the two wheels.The concentration of snow particles in the lower part of the bogie region was high,whereas that in the upper part was low.Only a small portion of the snow particles in the bottom airflow entered the bogie region with the upward airflow.The windward area of structures such as the frame,wheelset,brake disc,and the lower part of the brake caliper,was the concentrated collision part of the snow particles.The number of snow particles that impacted those structures was more than an order of magnitude higher than that in other parts of the bogie.When the train’s running speed was 300 km/h,the surface of the lower part of the bogie had a high impact rate of snow particles,which was in the range of 20-56 m/s.The impact rate in the upper part of the bogie was less than 20 m/s,and the average surface impact velocity at its top surface was less than 2 m/s.When the train ran at high speed,most of the areas where snow particles were concentrated had a higher than normal impact speed.