挡风墙结构对高速列车气动性能的影响

The Influence of Wind Wall on High-speed Train Aerodynamic Performance

高速铁路挡风墙结构能够有效改善大风条件下高速列车的气动性能,不同线路条件下的挡风墙结构对列车气动性能的影响也不同。针对CRH_2型车3辆编组外形1:1模型,采用数值计算方法分析了在路堤和桥梁两种线路条件下挡风墙结构对列车气动性能的影响,为保证计算方法的准确性,通过风洞试验对计算方法和网格离散进行了验证。研究结果表明:对于路堤运行条件,安装挡风墙后,列车周围流场的复杂度增加,车体表面多为负压,显著减小车体两侧的压差,能够有效改善列车的气动性能;对于桥梁运行条件,开孔式挡风墙结构能够起到明显降压作用,从而减弱横风对列车迎风侧的直接冲击,改善列车的气动性能。计算结果在后期试验中得到了验证,为兰新二线大风试验方案的制定和顺利开行提供了科学支撑。

The wind-wall structure of high speed railway can effectively improve the aerodynamic performance of high-speed train under the strong wind.The different wind-wall structures under the line condition have the different effects on the train aerodynamic performance.In this paper,three dimension full scale model of CRH2 EMU were established,and numerical calculation method were used to analyze the aerodynamic performance effect of train produced by the wind-wall structure in the embankment and bridge condition.In order to guarantee the accuracy of the calculation method,wind tunnel test results were used to verify the calculation method and the discrete grid.The study results showed that：in the condition of embankment,the complexity of the flow field around the train increased,and the pressure difference on both sides of the vehicle reduced greatly after the installation of wind-wall,negative pressure is produced more on surface of body,so the aerodynamic performance can be effectively improved.In the condition of bridge,the opening type wind wall structure can reduce the pressure significantly,so it can Weaken the direct impact on the train windward and improve the aerodynamic performance.