The present study was performed to investigate the effect of jet Froude number, submergence factor, and boundary roughness on the submerged wall jets. The jet Froude number ranged from 4 to 10, the submergence factor ranged from 0.375 to 3.5, and the relative roughness ranged from 0.25 to 0.50. The results showed that the rough boundary could effectively reduce the hydraulic characteristic parameters. Compared to the smooth bed, the depression in water surface elevation at the beginning of submerged wall jet and the length scales along and vertical the flow direction over the rough bed decreased. The maximum velocity u _m of cross-section appeared farther away from the bed, and the decay of it along the distance was faster than that on the smooth bed. The decay of the ratio for the maximum velocity to the nozzle velocity u ₁ had two stages along the distance x/L, where L was the longitudinal distance at which u _m = 0.5u ₁. The first decay stage was like that in a plane wall jet, and the second decay stage was more and more like a free jump with the decrease of Froude number and submergence factor. While the decay of maximum velocity has good similarity using the new length scale L*, where L* was the longitudinal distance at which u _m = 0.2u ₁. The shear force coefficients for submerged wall jets on corrugated beds were much smaller than those for free jumps on smooth beds, let alone for free jumps on corrugated beds.

本研究旨在研究射流弗劳德数、淹没因子和边界粗糙度对淹没壁射流的影响。射流弗劳德数为4~10，淹没因子为0.375~3.5，相对粗糙度为0.25~0.50。结果表明，粗糙边界可以有效降低水力特性参数。与光滑床相比，潜壁射流开始时水面高程的凹陷和粗糙床沿和垂直流向的长度尺度减小。最大速度u _m断面出现在离床层较远的地方，沿距离衰减比在光滑床层上的要快。最大速度与喷嘴速度u ₁之比的衰减沿距离x / L有两个阶段，其中L是u _m = 0.5 u ₁时的纵向距离。第一个衰减阶段就像在平面壁射流中一样，随着弗劳德数和淹没因子的减小，第二个衰减阶段越来越像自由跳跃。而使用新的长度尺度L *，最大速度的衰减具有很好的相似性，其中L* 是u _m = 0.2 u ₁时的纵向距离。水下壁射流在波纹床上的剪切力系数比在光滑床上自由跳跃的要小得多，更不用说在波纹床上自由跳跃了。