超高速列车受电弓气动特性分析

Analysis on Aerodynamic Characteristics of Pantograph in Super-high Speed Train

基于超高速运行条件,通过建立单臂受电弓模型,在横风条件下采用分离涡模拟方法研究受电弓在不同工况下的非定常气动特性,分析其三维绕流场的涡量、流线、压力以及受电弓气动力、力矩系数的时程变化规律及频域特性,探讨了该型受电弓在高速与超高速运行时绕流特性的差异。结果表明:由于超高速运行导致受电弓气动荷载平均值和振幅增大、振荡周期减小以及对应频谱变宽,由非定常升力和横风的作用引起的俯仰力矩和侧偏力矩的作用显著,导致受电弓在垂直方向的振动加剧,故结构相对紧凑的单臂受电弓有利于减小纵向振动;但其底架高度较高,在相同的升弓角度下上臂与下臂的空间夹角减小,导致上臂与下臂连接处出现范围较大的低速尾流,小尺度分离涡的结构及分布复杂,研究结果对横风作用下受电弓气动特性研究及应用具有重要意义和价值。

Based on the high-speed train pantograph, a single-arm single-slide pantograph model was established. The numerical simulation method was used to study the unsteady aerodynamic characteristics of the pantograph under different working conditions with crosswind conditions. The vortices, streamline, pressure and the variation law of the aerodynamic power and moment coefficients, and the frequency domain characteristics of the three-dimensional flow field were analyzed. The difference of flow characteristics between single-arm single-slide pantographs at high speed and super-high speed was discussed. The results show that due to the super-high speed running, the average and amplitude of the aerodynamic load of the pantograph increase, the oscillation period decreases, and the corresponding spectrum becomes wider. The effects of pitching moment and side moment caused by unsteady lift and crosswind were significant. The vibration of the pantograph in the vertical direction was intensified, so the single-arm pantograph with relatively compact structure is beneficial to reduce longitudinal vibration. However, the height of the underframe was larger and the angle of the pantograph was smaller, these result in: a large-scale low-speed wake occurs at the junction of the upper arm and the lower arm, and the structure and distribution of the small-scale separation vortex are relatively complicated. The research results have important significance and value for the study and application of unsteady aerodynamic characteristics of pantograph with cross-wind.