风屏障高度对城轨专用斜拉桥车桥系统气动特性的影响

Effect of wind barrier's height on train-bridge system aerodynamic characteristic of cable-stayed bridge for urban railway transportation

在综合考虑风屏障高度对桥梁及桥上列车气动特性影响的前提下,采用风洞试验和数值模拟相结合的方法,研究在桥梁上设置不同高度风屏障的情况下列车与桥梁的气动力系数以及车桥系统周围的流场分布情况。研究结果表明:随风屏障高度增加,桥梁的阻力系数明显增大,而桥上列车的阻力系数相应减小,桥梁与列车的升力系数变化不明显;在侧风作用下,风屏障高度对处于桥面迎风位置列车的所受气动力影响较明显;风屏障高度对车桥系统周围流场的影响较明显,当风屏障高度增加时,梁体迎风面正压区显著增大;车体迎背风面的压力分布不仅受风屏障高度的影响,而且受列车在桥面的位置的影响。

In order to consider the effects of wind barrier＇s height on both bridge deck and train, a method that combines wind tunnel test and numerical simulation was adopted to study the aerodynamic coefficients of bridge deck and train and the flow field around train-bridge system with wind barriers at different heights. The results show that with the increase of wind barrier＇s height, aerodynamic coefficient of the bridge increases obviously, and yet aerodynamic coefficient of the train decreases. On the contrary, lift coefficient of bridge and train is almost unchanged. The wind barrier＇s height has a more remarkable influence on the aerodynamic force on the train in windward cases than that in leeward cases. Moreover, the wind barrier＇s height can impact the flow field around train-bridge system. With the increase of wind barrier＇s height, the positive pressure zone on the windward side of the bridge deck increases obviously. Besides that, the wind pressure distribution around train depends not only on the wind barrier＇s height but also on the position of the train on bridge deck.