Numerical Investigation of the Flow Pattern and Energy Dissipation of Interval-Pooled Stepped Spillways

Spillways are widely used to transfer excess water in reservoirs to the downstream and energy of the high-speed flows is also dissipated in this process. Since the 1970s, in order to reduce the velocity of the flow transferring to the stilling basins, stepped spillways have been investigated by many researchers. In recent years, as an improvement of the flat stepped spillway, pooled stepped spillways has been proposed due to its better aeration performance and energy dissipation rate. However, insights into this novel type of stepped spillway are still relatively limited. There were little people to study the interval-pooled stepped spillways with fewer materials and macro-roughness. This present work numerically studied four types of stepped configurations with a channel slope of θ = 26.6°. Combined with the VOF method, RNG k-ɛ turbulence model was used to investigate the hydraulic properties of the flows over interval-pooled stepped spillways. The numerical results of the flat stepped spillway were fairly consistent with the experimental data. In all conditions, the flow pattern and energy dissipation of the interval-pooled stepped spillways are strongly influenced by the height of the pool. The interval-pooled stepped spillways configuration exhibited more unsteady flow patterns than traditional stepped spillways.