In this study, a series of laboratory tests were performed to investigate the effects of side ramp slope, crest length, and porous media properties on the flow regimes, water-surface profiles, discharge coefficients, and energy dissipation in embankment gabion weirs with upstream and downstream slopes. 24 physical models of solid and gabion weirs with three different upstream/downstream slopes (90°, 45° and 26.5°) were created. To investigate the complexity of flow over the porous-fluid interface and through the porous material, three-dimensional (3D) numerical simulations were developed. In numerical simulation, the standard k-ε turbulence model was utilized. A structured mesh domain was used to simulate the physical model. Water surface profiles above the porous weirs were used for comparison between the numerical simulations and measured data. These comparisons helped determine variables in the numerical simulations. Numerical simulation enables visualization of streamlines around and through the gabion weirs. In addition, mean stream wise velocity profiles above and within the porous structures were obtained. Numerical simulations showed that a reduction in the slope of the upstream face leads to an increased curvature of streamlines and the velocity distribution exhibits a non-uniform wavy shape due to the geometrical properties of the weirs. As the velocity profiles move downstream, the velocity distribution within the porous structures were more affected by the presence of the pores. The experimental results show that decreasing upstream slopes, from 90° to 26.5°, leads to decreased discharge coefficients. However, in all cases, gabion weirs lead to greater discharge coefficients than those of similar solid weirs. For milder side slopes, discharge ratios (flow passing through all faces of the gabion weirs over the inlet discharge) decreased nonlinearly. Moreover, with increasing the inlet discharge, relative energy dissipation was reduced up to 45% in gabion weirs.

在这项研究中，进行了一系列实验室试验，以研究边坡坡度、顶部长度和多孔介质特性对上游和上游的路堤石笼堰的流态、水面剖面、流量系数和能量耗散的影响。下游斜坡。创建了 24 个固体和石笼堰物理模型，具有三个不同的上游/下游坡度（90°、45° 和 26.5°）。为了研究在多孔流体界面上和通过多孔材料的流动的复杂性，开发了三维 (3D) 数值模拟。在数值模拟中，标准的k-ε使用湍流模型。结构化网格域用于模拟物理模型。多孔堰上方的水面剖面用于数值模拟和测量数据之间的比较。这些比较有助于确定数值模拟中的变量。数值模拟使围绕和穿过石笼堰的流线可视化。此外，获得了多孔结构上方和内部的平均流向速度分布。数值模拟表明，上游面坡度的减小导致流线曲率增加，并且由于堰的几何特性，速度分布呈现出不均匀的波浪形。随着速度剖面向下游移动，多孔结构内的速度分布更受孔隙存在的影响。实验结果表明，上游坡度从 90° 减小到 26.5° 会导致流量系数降低。然而，在所有情况下，石笼堰比类似的实心堰产生更大的流量系数。对于较缓和的边坡，流量比（通过石笼堰所有面的流量超过入口流量）呈非线性下降。此外，随着入口流量的增加，石笼堰的相对能量耗散减少了 45%。对于较缓和的边坡，流量比（通过石笼堰所有面的流量超过入口流量）呈非线性下降。此外，随着入口流量的增加，石笼堰的相对能量耗散减少了 45%。对于较缓和的边坡，流量比（通过石笼堰所有面的流量超过入口流量）呈非线性下降。此外，随着入口流量的增加，石笼堰的相对能量耗散减少了 45%。