Numerical Simulation of the Effect of Single Guide Vane Installation on the Hydraulic Performance of Side Weirs in Converging Channels

This study examined a new solution to increase the outflow efficiency (e: ratio of spilled discharge to the incoming flow discharge) of side weirs in converging sections by installing a single guide vane (G.V.) on the crest of the side weirs using numerical simulation. A Flow-3D numerical model was used for performing simulations. The scenarios were performed at six G.V. installation angles, three lengths, and three installation positions. The findings indicated that the best installation angle for G.V. is 120 degrees. A G.V. installed at this angle with a length equal to 20% of the width of the upstream channel ( \(ZR=20\text{\%}\) $ZR=20\text{\%}$ ) in the middle of the side weir crest ( \(XR=0.50)\) $XR=0.50)$ increased the outflow efficiency by 14% compared to the control scenario. However, the installation position of G.V. with different lengths had different effects on efficiency. The data also revealed that the installation of G.V. with \(ZR=30\text{\%}\) $ZR=30\text{\%}$ in \(XR=0.50\) $XR=0.50$ decreased outflow efficiency by almost 11% due to the formation of the vortex and air entry compared to the case where G.V. with \(ZR=20\text{\%}\) $ZR=20\text{\%}$ was installed in the same place, with the efficiency in this scenario being nearly equal to that of the control scenario ( \(e=62\text{\%}\) $e=62\text{\%}$ ).