Numerical study of bed slope change effect of circular channel with side weir in supercritical flow conditions

In this numerical study, the pattern and the field of the passing flow through circular channels with the side weir in supercritical flow conditions are simulated using the FLOW-3D model. First, the numerical model results are validated with the experimental data and a good agreement between the results is obtained from the numerical simulation and the experimental data. Then, the effects of the slope change of the circular channel bed on the flow free surface, the discharge of the side weir, the Froude number at the end of the side weir upstream, the discharge coefficient of the side weir, the specific energy and the slope of the S3 profile are investigated. In this study, the flow field turbulence and variations of the free surface computational field are simulated using the RNG k - ε turbulence model and the volume of fluid (VOF) method, respectively. In practice, transmission channels used in irrigation networks and urban sewage disposal systems are steep. Therefore, the main purpose of this computational fluid dynamics (CFD) study is investigating the effect of the bed slope change of circular channels with side weir in supercritical flow conditions on the pattern and the structure of these types of flows.