大风环境列车横截面外形优化

列车经过大风环境时引起的列车稳定性变化影响列车行车安全与乘坐舒适性。优化列车横断面可以提高列车在横风作用下气动性能,降低倾覆危险。借助数值模拟手段,通过优化截面内倾角位置高度等7个几何参数,得到倾覆力矩随参数变化的规律,确定优化中需重点关注的参数。研究结果表明,倾覆力矩随顶部折角与底部折角的变化为非单调增长,而随其他部位的变化呈现单调趋势,优化得到的组合截面比原始截面横向力下降28. 28%、升力大小下降42. 85%、倾覆力矩减小45. 91%。优化后的列车横截面模型与原始断面相比,横向力增长了24. 28%,升力和倾覆力矩分别下降了75. 99%和27. 19%。倾斜条件下,优化后的列车截面模型倾覆力矩较原车模型下降了11. 22%。

Shape Optimization of Train Cross Section under Strong Wind Condition

Crosswind affects the stability of train and ride comfort of passengers.The aerodynamic performance of a train under crosswind can be effectively improved by optimizing the shape of the cross section of the train to reduce the overturning risk.This paper analyzed the effects of seven shape parameters on the aerodynamic performance by using numerical simulation.The critical parameters for optimizing were determined after the rule of overturning moment changing with parameters was obtained.Further optimization was conducted based on the real train cross section and the promising results were presented.The main conclusions are as follows:the overturning moment of the initial section increases non-monotonically with the change of the top and the bottom incline angle,while varies monotonically with the change of other parts.The lateral force,lift and overturning moment of the combined optimized shape decreased 28.28%,42.85%,45.91%,respectively,compared with the original shape.Based on the initial study,the lateral force of the optimized train increased 24.28%,while the lift and the overturning moment decreased 75.99%,27.19%,respectively.In the case of the inclined position of the train,the optimized train shape remains a better aerodynamic performance,and the overturning moment decreases 11.22%compared with the original section.