单线路堤上挡风墙高度研究

Height of wind barrier on embankment of single railway line

采用数值模拟计算的方法,对单线路堤上不同高度单、双侧挡风墙对列车气动性能的影响进行研究。研究结果表明:安装挡风墙后,车辆的气动力系数远远小于无挡风墙时的气动力系数,车辆的迎风面受到的压力由大部分正压转变为大部分负压,车辆顶部受到的负压明显减小;挡风墙的不同高度对车辆的气动性能有明显影响,挡风墙高度较低时,横向力系数为正值,随挡风墙高度的增加而减小,达到一定高度后,由正值变为负值,而倾覆力矩系数则正好相反;对于单侧挡风墙,在挡风墙高度为1.85 m时,车体的倾覆力矩系数为0,其合理高度应为1.85 m;对于双侧挡风墙,当挡风墙高度为2.00 m时,倾覆力矩系数为0,因此,挡风墙合理高度为2.00 m。

The effect of different heights of wind barrier on double-side or single side of embankment to train aerodynamics performance was researched by numerical simulation. The results show that when wind barrier is installed, train aerodynamic coefficients are much less than those without wind barrier and that the pressure on windward surface of train changes from positive to negative, and negative pressure on roof of train decreases obviously. Different heights of wind barrier have great effect on train aerodynamic performance, the side force coefficient of train is positive when wind barrier is lower and its value decreases with the increase of height of wind barrier and it changes to negative when the height reaches certain height, while it is directly opposite to the ovemu＇ning moment coefficient of train. To the single wind barrier, when its height is 1.85 m, train＇s overturning moment coefficient is almost equal to 0, so its reasonable height should be 1.85 m, while to the double-side wind barrier, when its height is 2.0 m, train＇s ovemarning moment coefficient is almost equal to 0, so its reasonable height should be 1.85 m.