This paper focuses on the aerodynamic characteristics of trains on a non-uniform double-track railway bridge under crosswinds through a scaled 1:40 sectional model wind tunnel test. Pressure measurements of five cross-sections of two types of trains, one with round roof and one with blunt roof, at the upstream and downstream tracks of the bridge were conducted under crosswinds with wind attack angles between −12° and 12°. The mean wind speed and turbulence intensity profiles around the windward surface of the train in the downwind and upward directions were also measured using cobra probe to obtain the boundary layer above the bridge surface. The results show that the shapes of train and bridge, as well as the wind attack angle, affect the aerodynamic characteristic of the train on the non-uniform bridge girder. The mean and fluctuating pressure coefficients are similar for all five cross-sections of the trains while the train is at the upstream track. However, when the train is at the downstream track, the extreme mean and fluctuating pressure coefficients around the windward and top surfaces of each cross-section on the train are different. At the downstream track, the mean wind speed profile and the turbulence intensity profile around the top of the train vary dramatically due to the separation flow caused by the leading edge of the bridge girder.

本文通过比例为1:40的截面模型风洞试验，重点研究了横风作用下非均匀双轨铁路桥梁上火车的空气动力学特性。在风速为-12°到12°的侧风作用下，在桥的上游和下游轨道上对两种类型的火车的五个横截面进行压力测量，一种是圆形屋顶，另一种是钝顶。还使用眼镜蛇探针测量了列车在顺风方向上的迎风面周围的平均风速和湍流强度分布，以获得桥面上方的边界层。结果表明，列车和桥梁的形状以及迎风角度会影响列车在非均匀桥梁上的空气动力特性。在火车处于上游轨道时，火车的所有五个横截面的平均压力系数和波动压力系数都相似。但是，当火车位于下游轨道时，火车上每个横截面的迎风面和顶面附近的极端平均压力系数和波动压力系数都不同。在下游轨道，由于桥梁前缘引起的分离流，列车顶部周围的平均风速分布和湍流强度分布变化很大。