U-shaped channels along the side weir for subcritical and supercritical flow regimes

In this study, some relationships between discharge and geometrical and hydraulic characteristics are proposed using the two-dimensional conduit outlet theory in order to estimate the side weir discharge on U-shaped channels for subcritical and supercritical flow regimes. The proposed relationships predict the side weir discharge with an acceptable accuracy. Also, this study presents a 3D flow field simulation in the U-shaped channels along a side weir by the renormalization-group (Formula presented.) turbulence model and volume-of-fluid scheme in subcritical and supercritical flow conditions. A good agreement was obtained between the results of the numerical simulation and the experimental measurements for both flow regimes. According to numerical simulation results, a surface jump with a stagnation point happens at the side weir downstream end for both flow conditions. Also, a secondary flow cell is occurred after the side weir and developed towards the U-shaped channel downstream in subcritical flow condition. Then, the effects of the side weirs submergence on the flow pattern in the U-shaped channels are investigated. The drop and slop of the flow free surface profiles for the submerged side weir is less than the non-submerged weir in subcritical and supercritical flow regimes. © 2018 Indian Society for Hydraulics.