Study of Hydraulic Characteristics of Circular Vertical Spillway Using Numerical Model

Circular vertical Spillway with various inlet forms is very effective, when there is not enough space for the other spillway. Hydraulic flow in vertical circular spillway is divided into three groups: free, orifice and under pressure (submerged). In this research, hydraulic characteristics are investigated in vertical circular spillway by using numerical model. Hydraulic characteristics are investigated such as upper and lower nappe profiles, relation between discharge and upstream water levels, and discharge coefficient in numerical modeling and experimental conditions. The mesh with 10602 nodes, turbulent model k- standard and the standard wall function, provide the best results for modeling the flow in a vertical circular Spillway. There was a good agreement between numerical and experimental results in the upper and lower nappe profiles. In study of water level over crest and discharge, in low water levels, the results of numerical modeling are good agreement with experimental, but with increasing water level, the difference between the numerical and experimental discharge to be more. In the study of the flow coefficient, by decreasing in P/R ratio the difference between the numerical and experimental result increases.