The stepped spillway is a cost-effective hydraulic structure to dissipate the energy of large water flow over the spillway of a dam. In this study, the focus was placed on the effects of triangular prismatic elements (TPEs) on the hydraulic performance of a stepped spillway. Nine stepped spillway models were experimentally and numerically investigated with different shapes and layouts of TPEs. To adopt a proper turbulent model, RNG k-ε and standard k-ε models were utilized. The computational model results satisfactorily simulated the complex flow over the stepped spillway of experiment cases, including velocity distributions and pressure profiles on the step surfaces. The results indicated that the installation of TPEs on stepped spillways can be an effective way to reduce cavitation effects. Installing TPEs on stepped spillways increased the energy dissipation rate up to 54%. The performance of stepped spillways was improved when TPEs were spaced more closely together. Furthermore, the relationships between the roughness coefficient (f) and the ratio of the critical depth to the step roughness (yc/k) were obtained with high accuracy using the experimental data.

阶梯式溢洪道是一种具有成本效益的水工结构，用于消散大坝溢洪道上的大水流能量。在这项研究中，重点放在了三角棱柱元件 (TPE) 对阶梯式溢洪道水力性能的影响。九个阶梯式溢洪道模型对不同形状和布局的 TPE 进行了实验和数值研究。采用适当的湍流模型，RNG k - ε和标准k - ε模型被使用。计算模型结果令人满意地模拟了实验案例阶梯溢洪道上的复杂流动，包括阶梯表面的速度分布和压力分布。结果表明，在阶梯式溢洪道上安装 TPE 是减少空化效应的有效方法。在阶梯式溢洪道上安装 TPE 可将能量耗散率提高 54%。当 TPE 更紧密地间隔开时，阶梯式溢洪道的性能得到改善。此外，粗糙度系数 ( f ) 与临界深度与阶梯粗糙度的比值 ( yc / k ) 之间的关系是使用实验数据以高精度获得的。