To reduce the trend of scouring, understanding the flow pattern around the bridge piers is necessary. By using hydraulic structures such as submerged vanes, it is possible to alter the flow pattern of water, thus scouring process and sediment transport in riverbeds. Since the scouring mechanism for pier groups differs from single pier, experiments were conducted in a 180° sharp bend channel in the laboratory to investigate the flow pattern around pier group and single pier under the influence of 25% submerged vanes. Furthermore, a comparison was made between the flow patterns in single pier and pier group conditions. Three-dimensional velocities along the bend and different depths were measured using an Acoustic Doppler Velocimeter (ADV(. The results suggest that the maximum vorticity value at the apex position of the bend (location of piers) and the maximum secondary flow value, at the distance between the piers and the vanes, were found to be, 0.15 and 0.89, respectively. In the twin pier experiment, the maximum Reynolds shear stress value \({\tau }_{yx}\) decreased by about 36%, and the minimum value decreased by about 49% compared to the single pier experiment. The final results indicated that using submerged vanes obtained the maximum \({\tau }_{yx}\) and \({\tau }_{zx}\) near the vanes. Near the bed and mid-depth of the water flow, the geometric location of the maximum velocity also occurred around the vanes in both experiments. Therefore, the vanes are important in altering the water flow pattern, diverting the flow from around piers and consequently reducing the bridge pier scouring.

为了减少冲刷的趋势，了解桥墩周围的水流模式是必要的。通过使用水下叶片等水工结构，可以改变水的流动模式，从而改变河床的冲刷过程和沉积物输送。由于群墩冲刷机理与单墩不同，在实验室180°急弯通道中进行实验，研究25%淹没叶片影响下群墩和单墩周围的流态。此外，还对单墩和群墩条件下的流型进行了比较。利用声学多普勒测速仪（ADV）测量了沿弯道和不同深度的三维速度。结果表明，弯道顶点位置（桥墩位置）处的最大涡度值和弯道处的最大二次流值桥墩与叶片之间的距离分别为 0.15 和 0.89，在双桥墩实验中，最大雷诺剪应力值\({\tau }_{yx}\)降低了约 36%，并且与单桥墩实验相比，最小值下降了约49%，最终结果表明，使用浸没叶片获得了最大值\({\tau }_{yx}\)和\({\tau }_{zx}\。 ）在靠近水流床和中间深度的位置，在两个实验中最大速度的几何位置也出现在叶片周围，因此，叶片对于改变水流模式、使水流转向很重要。桥墩周围，从而减少桥墩冲刷。