Azam Dolatshah - Islamic Azad University, Dezful Branch, Dezful, Iran
Hasan Imani Khoshkho - Islamic Azad University, Harsin Branch, Harsin, Iran
Mahmoud Mashal - University of Tehran, Tehran, Iran
Najaf Hedayat - Islamic Azad University, Dezful Branch, Dezful, Iran

Present study was conducted with application of numerical methods for investigating the turbulent flow over ogee stepped spillways. For this purpose, the Finite Volume-Finite Difference Method (FV-FDM) was employed for numerical modelling of an ogee stepped spillway physical model belonging to a previous research study. Various parameters over the steps like water surface profile, pressure, and velocity of flow over steps were studied. The perfect conformity of numerical and laboratory results is clearly observed both visually and statistically. Then, as a result of development of the numerical model, steps’ dimensions and geometries were changed and various spillways with smaller, larger, curved, obstacle, and steeped steps (and even a smooth ogee spillway) were investigated. Different properties of flow over steps were studied more and energy dissipations were obtained using the relevant hydraulic formulation. Results were compared with each other to survey the flow over the spillways. Results show that specific forms of steps make the flow more turbulent, and dissipate the energy better in addition to reduce the cavitation risk.

stepped spillways, turbulent flow, Computational Fluid Dynamics (CFD), Finite Volume Method (FVM), Finite Difference Method (FDM)