This paper presents the results of a LES of turbulent surface jets over a submerged weir. The mean flow and turbulent structures are presented for both flat and deformed bed conditions. LES results with the scour hole reveal that the separated shear layer is extended by about three times, locating the reattachment point further downstream. In addition, the presence of the scour hole increases both total and maximum TKE and decreases near-bed TKE. Quantitatively, with the scour hole, the maximum near-bed TKE is decreased by 50%. It turns out that the area of high instantaneous bed shear stress does not match with that of high time-averaged bed shear stress, but does match well with that of the high near-bed TKE. The vortices generated by the weir propagate differently with and without the scour hole and shed light on the generating mechanism of a scour hole.

本文介绍了水下堰上湍流表面射流的 LES 结果。平均流和湍流结构均针对平坦和变形的床条件进行了介绍。冲刷孔的 LES 结果表明，分离的剪切层延伸了大约三倍，将重新附着点定位在更下游的位置。此外，冲刷孔的存在增加了总 TKE 和最大 TKE，并降低了近床 TKE。定量地，随着冲刷孔，最大近床 TKE 降低了 50%。结果表明，高瞬时床层剪应力区域与高时间平均床层剪应力区域不匹配，但与高近床 TKE 区域匹配良好。