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

Abstract

ABSTRACT 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 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.