Simulation of Flow Over Cylindrical Weirs Using Fluent Model and Comparison with Experimental Data

Cylindrical weir is one of the broad-crested weirs used extensively due to steady state flow pattern and free passing of suspended materials over it. In this study, flow conditions over five physical models of cylindrical weir were tested and the effects of parameters such as weir diameter, hydraulic head at the upstream side and negative pressure on the weir were investigated. The flow was also simulated using turbulence model by Fluent software and the results were compared with those from the physical model. There was a rise in coefficient of discharge when the total head of flow and negative pressure over the weir were increased. The average relative errors of Fluent software in simulation of upstream flow depth, depth of flow over the weir and coefficient of discharge were 0.914%, 1.39% and 4.172%, respectively. By considering the hydraulic properties of flow over the cylindrical weir, a good agreement between the results of Fluent software and physical model was confirmed.