强横风环境下棚车侧壁外形气动性能

Aerodynamic performance of sidewall shape of boxcar under strong crosswind

强横风引起的气动横向力和气动升力是造成列车被吹翻事故的主要原因。空棚车由于其侧壁迎风面积大且质量轻,很容易在强横风作用下发生倾覆事故。采用流场数值计算方法,对垂直侧壁、弧形侧壁和外折形侧壁3种棚车外形方案,研究了横风作用下的棚车空气动力特性:气动横向力、升力和气动倾覆力矩。研究结果表明:车体受到的气动倾覆力矩主要是由气动横向力产生的;弧形侧壁和折形侧壁可以有效地改善车辆横向气动性能,降低车辆的气动倾覆力矩,提高车辆的稳定性;与垂直侧壁棚车相比,当车体宽度为3.2 m时,弧形侧壁和外折形侧壁棚车的气动倾覆力矩均可以下降21%左右,空载棚车倾覆临界风速可以提高2.7 m2.s-1。

The transverse force and air lift force caused by strong crosswind are the main factors of train overturning, unloaded boxcar can easily be overturned by strong crosswind because of its large sidewall area and underweight. So flow field numerical computation was completed in order to look for an optimum project of sidewall shape among the upright sidewall, bulgy-arc sidewall and bulgy-slope sidewall, the aerodynamic performance of boxcar suffering from crosswind was studied, such as the transverse air force, air lift force and overturning moment. The result shows the bulgy-arc sidewall and bulgy-slope sidewall can reduce the overturning moment effectively and improve train＇s stability under strong crosswind to greater extent than the upright sidewall, when the width of boxcar is 3.2 m, boxcar sidewall with bulgy-arc and bulgy-slope compared with upright, its coefficient of overturning moment decreases to about 21% and the critical wind speed increases to 2.7 m^2 ·s^-1 for unloaded boxcar. 2 tabs, 4 figs, 8 refs.