A 3-Dimensional Numerical Simulation of Flow Over a Broad-Crested Side Weir

Abstract

One of the applications of side weirs is predicting the accurate flow measurement in irrigation and floodwater spreading systems. However, the hydraulic behavior of this type of weir is complex and difficult to predict accurately. In this study, the flow over a broad-crested side weir is numerically investigated based on experimental data under subcritical condition. The numerical model considers flow over side weir using Reynolds’s average Navier–Stokes (RANS) equations. The renormalization-group (RNG) k-ε model was used to account for turbulence modeling and the volume of fluid (VOF) scheme was also used in the model to find free surface of flow. The simulation results were validated by experimental data. The simulation results provided detailed analysis of flow pattern, pressure distributions in longitudinal and transverse sections over the side weir. This study shows that existing numerical models using RANS are useful in design of side weirs.