Steeped spillway as a mean for energy dissipation – a review

Abstract

Stepped spillways are spillways provided by steps that are used to dissipate energy and reduce the scour and erosion that occur at the end of the hydraulic structures. Since the spillway is one of the parts of the dam used to get rid of excess water during floods, spillways can be constructed in various forms and sizes depending on the geology of the dam site and the hydraulic conditions of the flow. The stepped type was chosen because it dissipates energy and reduces the size of the basin at the end of the structure. The aim of the research is to review most of the studies that dealt with the subject of stepped spillways as energy dissipaters. This study collected much research on stepped spillways, some of which used physical models and others numerical models. These studies were performed to determine energy dissipation, flow properties, or type of flow in the stepped spillways and to study the effect of the shape of the steps on energy dissipation. The results showed that some studies indicated that when the flow over the stepped spillways is in the form of jet or free flow, it increases the efficiency of energy dissipation and reduces the length of the hydraulic jump. It is worth mentioning that some studies used software such as ANSYS, while others used artificial intelligence (AI) techniques like genetic programming and fuzzy logic.

Keywords

• energy dissipation
• stepped spillways
• nappe
• transition and skimming flow
• physical and numerical model