Siphon-shaft spillways are constituted by covering above a shaft spillway with a hood that creates siphonic pressure. This study focused on the aeration the flow through the aerator holes placed on the hood to prevent cavitational damage in high-head siphon-shaft spillways. Three-dimensional computational fluid dynamics (CFD) technique using finite-volume method to solve Reynolds-averaged Navier–Stokes (RANS) equations for the incompressible viscous and turbulent fluids motion was performed to analyze the full-scaled two-phase numerical models. The volume of fluid (VOF) scheme was used to simulate two-phase (water–air) flow, by defining the volume fraction for each of the fluids throughout the solution domain. The accuracy of the numerical model was tested using a procedure recommended by American Society of Mechanical Engineers (ASME) for CFD applications. The numerical results showed that the aeration is highly effective in reducing siphon sub-pressures and cavitation. The optimal relative aeration diameter of 0.45 provided sufficient air entrainment to protect from cavitation and did not decrease the discharge performance too much.

虹吸式竖井溢洪道是通过在竖井溢洪道上方覆盖一个能产生虹吸压力的罩子构成的。这项研究的重点是通过放置在引擎盖上的曝气孔的气流进行曝气，以防止高水头虹吸竖井溢洪道中的气穴损坏。三维计算流体动力学 (CFD) 技术使用有限体积法求解不可压缩粘性和湍流流体运动的雷诺平均纳维-斯托克斯 (RANS) 方程，以分析全尺寸两相数值模型。通过定义整个溶液域中每种流体的体积分数，使用流体体积 (VOF) 方案来模拟两相（水-空气）流动。使用美国机械工程师协会 (ASME) 推荐的 CFD 应用程序测试数值模型的准确性。数值结果表明，曝气在降低虹吸分压和气蚀方面非常有效。0.45 的最佳相对曝气直径提供了足够的空气夹带以防止气蚀，并且不会过多降低排放性能。