Flow Pattern and Energy Dissipation in Stepped Spillways With Non-Uniform Step Height Using the ANSYS CFX Software

The use of stepped spillways has been increasingly on the rise due to their low cost and high efficiency. Hence، growing attention has been paid to the studies in this field by dam engineers; however، most of these studies have focused on the stepped spillways with uniform step height at the cost of ignoring non-uniform step heights، which also demand particular attention. In this study، a physical model of Herat Dam for a 1. 3-m high stepped spillway with a slope of 19. 2 ° was used to verify the numerical model. Then، three types of stepped configurations were tested using computational fluid dynamics in the ANSYS CFX software for the flow range of. Further، a two-phase flow simulation was carried out for each configuration and all discharge ranges. The results were compared in terms of flow pattern، energy dissipation and aeration point. The results showed minor difference in terms of energy dissipation for nappe regime flow and marked difference in terms of skimming regime flow.