Numerical modeling of flow over an Ogee spillway and investigation of effect of downstream influences on discharge

Abstract

The main aim of this study was to investigate flow over an ogee spillway and simulating by numerical model. A commercially available computational fluid dynamics (CFD) program, which solves the Reynolds-averaged Navier-Stokes equations (RANS), was used to model the physical model setup. Flow over an ogee spillway has free surface and turbulent flow so that in some cases calculating flow rate and flow depths are difficult. Increasing in water level at downstream may cause reduce in discharge because of suction forces and negative pressure. In this study, different numerical turbulence models are used to predict discharge and compared with experimental results. In experiments, discharge and flow depths of physical model were recorded for 22 different total head over the crest. The results show that there is reasonably good agreement between the physical and numerical models for discharges.