Experimental Investigation of Hydraulic Jump in Side Weirs

Side weir as a hydraulic structure is widely used in water intakes. In addition، this structure is used as a protective structure at the end of the main channels to discharge excess water flow. In some cases a hydraulic jump is possible to occur along the spatially varied flow over the side weir and studies show that a few literatures are available for this condition of flow in the side weirs. This paper discusses water surface profile and discharge coefficient of the side weir under the condition of hydraulic jump occurrence in spatially varied flow. Values of the statistic indices R2 and RMSE between the observed and calculated quantities of discharge coefficient for the side weir were 0. 776 and 0. 005 respectively. A new method called «Calibrated Subramanya Method» was also developed to define the shape of water surface profile of hydraulic jump in side weirs. This method showed a good agreement with the experimental data. Studies show that the hydraulic jump in spatially varied flow has almost a constant shape with oscillations on the water surface.