Experimental and CFD Modeling of Hydraulic Jumps Forming at Submerged Weir

Abstract

Broad-crested weirs are defined as structures where the streamlines are parallel to each other and the pressure is hydrostatic over the horizontal crest. The water surface profile for submerged flow over weir was estimated through flume experimentation and compared with numerical model results. The numerical model was developed using ANSYS FLUENT version 15 in three dimensions (3D) with a standard k–e turbulent model. The Volume of Fluid (VOF) method was used to estimate the water level in each cell and includes tail water influence acting on a broad-crested weir. The agreement between the FLUENT model and the experimental results for water depth was good. Such conditions are often difficult to predict, particularly at onset of the hydraulic jump. The numerically derived pressure and velocity distributions over the weir are simulated in 3D. Good agreement was achieved between numerical and experimental discharge with a relative error of 6.6%. The relative error between the numerical and experimental coefficient of discharge was 7.7%.