突变风作用下路堑深度对高速列车气动性能影响

Influence of Cutting Depth on Aerodynamic Performance of High Speed Train under Sudden Wind

为了保证高速列车在大风环境下路堑中行驶的安全,建立了高速列车—路堑耦合的气动仿真模型,研究了不同风场环境下路堑深度对列车气动性能的影响.研究表明:高速列车的气动特性随着风载荷的突变,气动特性的变化情况复杂.横风环境下,路堑深度的增加有利于降低列车气动力,而在突变风环境下,突变风作用下列车的气动力随风速变化情况更为复杂.当路堑深度为变量时,列车的气动力整体上随着路堑深度增大而降低,深路堑相较于浅路堑升力峰值减小51%,横向力减小52%,侧滚力矩减小97%,摇头力矩减小92%,6 s以后风载荷的影响出现滞后现象.同一路堑深度下,与横风作用下的结果相比,风载荷发生突变对高速列车气动特性影响大得多,列车的气动力及力矩峰值波动25%以上.

In order to ensure the safety of high-speed trains running in the cutting in strong wind,a three-dimensional aerodynamic numerical model of high-speed train-cutting coupling was established.The influence of the cutting depth on the aerodynamic performance of the trains under different wind fields was studied.The results show that the aerodynamic characteristics of the high-speed trains are complicated with the abrupt change of wind load.Under the crosswind environment,the increase of cutting depth is beneficial to reduce the aerodynamic force of the train.While under the abrupt wind environment,the aerodynamic force of the train under the abrupt wind is more complicated.When the cutting depth is a variable,the aerodynamic force of the train as a whole is decreased with the increase of the cutting depth.Compared with the shallow cutting depth,the lift peak of the deep cutting,the lateral force,the rolling moment and the shaking moment are decreased by 51%,52%,97%and 92%respectively,and the influence of wind load after 6 S appears hysteretic phenomenon.Under the same cutting depth,compared with the results under the action of cross wind,the sudden change of wind load has a much greater impact on the aerodynamic characteristics of high-speed trains,and the peak aerodynamic force and moment of the trains are fluctuated by more than 25%.