FE modeling of flow over stepped spillways: A case study of spillway of Siah-Bishe dam

Stepped spillway is one of the common types of spillways for water projects, and nowadays, it is considered due to its many benefits and they are used in many dam construction projects. The correct design and ensuring from proper these spillways require accurate analysis of the flow and has always been among the concerns of the dam's experts. Nowadays, using computers and numerical methods are a powerful tool for analyzing the flow and designing of water structures, and it is very useful in designing the primary spillways and optimizing them along with the construction of the hydraulic model. In this study, numerical modelling of flow over stepped spillways with different steps are presented, as well as optimization of the heights of steps. Also, a case study has been carried out about the Siah Bishe Dam spillway, in which the advantages and disadvantages of the numerical methods have been provided for optimizing the design. The computational fluid dynamics module of the finite element ANSYS FLUENT software was applied to assess the velocity vectors and pressure of the flow. According to the real flow is turbulent, the k-epsilon flow model was used. The predicted velocity vectors and pressure by numerical model was compared to the values attained hydraulic model. The use of the results of this study will be useful for experts and stepped spillways designers.