横风下风阻制动板对高速列车气动性能影响的仿真分析

Impact Simulation Analysis of Wind Resistance Brakes on High-speed Train Aerodynamic Performance under Crosswind Conditions

[目的]随着列车运行速度的提高,采用多种制动方式成为高速列车紧急安全制动的有力保障,风阻制动作为轮轨黏着制动的补充而广受关注。风阻制动板安装后,将影响列车的流线型,在横风条件下甚至会影响列车运行安全。为保证列车在大风环境下的行车安全和制动性能,需要对横风下不同制动板形式对列车气动性能的影响规律进行深入研究。[方法]采用三维、定常、不可压缩N-S方程和k-ε两方程湍流模型,开展有无横风和不同制动板高度对高速列车流场规律和气动力的影响研究。[结果及结论]仿真研究结果表明,横风下列车车身和制动板的气动阻力沿车身方向递增,横向力则递减,当制动板高度从0.5 m提高到1.0 m时,制动板阻力占总阻力的比例从54.89%提高到69.92%,最高达到56 kN;制动板横向力占整体横向力的比例小于1%,不同高度制动板对列车整体横向力的影响较小;制动板对来流有一定的滞止作用,距离较近的制动板存在流场相互干扰;制动板对于横向力的影响较小。通过制动板的前期设计,风阻制动足以成为列车制动的有效方案,且对列车的运行稳定性影响较小。

[Objective]As the train operational speed increases,various braking methods become essential for ensuring high-speed train emergency safety braking.Wind resistance brakes,which complement wheel-rail adhesion brakes,have garnered extensive attention.The installation of wind resistance brake plates affects the train streamlined shape and can influence train operational safety under crosswind conditions.To ensure train operational safety and braking performance in high wind environments,it is necessary to thoroughly investigate the impact law of different brake plate configurations on train aerodynamic performance under crosswind conditions.[Method]Using three-dimensional,constant,incompressible Navier-Stokes equation and k-εtwo-equation turbulence model,the influence of crosswind existence and varying brake plate heights on of high-speed train flow field and aerodynamic force are investigated.[Result&Conclusion]Simulation research results indicate that under crosswind conditions,the aerodynamic resistance on train carbody and brake plates increases along carbody direction,while the lateral force decreases.When the brake plate height increases from 0.5 m to 1 m,the proportion of brake plate resistance in overall resistance rises from 54.89%to 69.92%,with the maximum reaching 56 kN.The proportion of brake plate lateral force in overall lateral force is less than 1%,indicating that different brake plate heights have relatively little impact on train overall lateral force.The brake plates have a certain stopping effect on the incoming flow,and there is flow field interference between closely spaced brake plates.The influence of brake plates on lateral forces is minor.With proper preliminary design of brake plates,wind resistance brakes can be an effective train braking solution with minimal impact on train operational stability.