Investigations of water flow behavior over different stepped spillway geometry

In this project, the spillway effects have been investigated by various spillway design analysis using ANSYS CFD Fluent software. The slope of all the models is held constant for each case and two types of slops considered in this research. The inlet boundary condition of the stepped spillway model is represented by the discharge. The outlet boundary condition of the spillway is set by pressure, velocity and volume of friction. The results observed that it is feasible to improve the hydraulic behaviors of a pool configurations in stepped spillway. The pools in this study present an overcome of the flow stability and energy dissipation issues. The pressure value at the beginning of the step in the pooled configuration was large, while for the notched pool the maximum pressure values decreased near the step pool. Pool configuration (simple or notched) did not have a significant influence on the location of air entrainment. Also, the air entrainment location (inception point) moves downward when increases the discharge rate. This result observes the importance of the spillway steps shape to generate the pressure force based on height of each step. Keywords: Spillway slop design, Volume of friction, Inception point