风障对桥上高速列车气动特性影响的风洞试验

Experiment study on the effect of wind barrier on aerodynamic characteristics of high-speed train on bridge

为考虑侧风作用下风障对桥上高速列车气动特性的影响,以高速列车与双线简支箱梁桥为原型,自主研制了缩尺比为1:20的风障-车-桥模型风洞试验模型装置。测试高速列车的头车、中车及尾车各自的气动力。分析风速、列车位于桥梁的横向位置、不同风障高度与透风率、风偏角对高速列车气动系数的影响,最后以静力轮重减载率作为风障防风效果评价指标,给出风障气动选型参数建议值。研究结果表明:雷诺数对车-桥系统的气动性能影响有限;桥梁上设置风障可明显减小列车所受气动力;列车位于迎风侧线路时运行时所受气动荷载较大;随着风障高度的增大,列车气动力系数减小;当风障增加到某一高度后列车气动系数基本不再随风障高度变化,但随着透风率增大而增大;当风偏角小于等于20°时,高度为4 m,透风率为0%风障的挡风效果较好,而当风偏角大于20°时,高度为4 m,透风率为30%风障的挡风效果较优。研究结论可为实际工程中风障气动选型提供参考。

In order to investigate the effects of wind barrier vehicle on the aerodynamic characteristics of a vehicle-bridge system under crosswind, a high-speed train model and simple support bridge with double lines were designed to measure the aerodynamic forces acting on the vehicles and bridge by a self-developed wind tunnel test model with a scale of 1:20. The aerodynamic force coefficients of head train, middle train, and rear train of high-speed train were tested. Wind speed, laterally relative position of vehicle and bridge, the height and ventilation of the wind barrier, and yaw angle were investigated to demonstrate their effects on aerodynamic force coefficients of vehicles on bridge. Based on the criteria of static percent of wheel load, the optimal aerodynamic parameters of wind barriers were selected accordingly. The results show that the impact of Reynolds number on vehicle-bridge system is limited; the bridge structure arranged on the wind barrier can obviously reduce the train for the aerodynamic force; the train running in windward is greater than that in leeward; aerodynamic force coefficients of the train tend to increase with the increase of height of wind barrier, and when wind barrier is high enough, it has no influence on the aerodynamic forces, but the coefficients of the train increase with the increase of wind ventilation; when the yaw angle is below or equal to 20°, the bridge is provided with 4 m and 0% ventilation rate wind barrier structure is good, but when the yaw angle is greater than 20°, the performance of 4 m and 30% ventilation rate, wind barrier structure is the most reasonable. The research conclusion can guide significance and reference value in selecting the concrete wind barrier parameters.