Experimental investigation of screens as energy dissipaters in submerged hydraulic jump

Abstract

This study investigated the effectiveness of screens as energy dissipaters in small hydraulic structures using physical experiments. In the experimental design, the Froude number, screen arrangements, and screen porosity were the major controlling parameters. The experiments covered a range of Froude numbers between 2.5 and 8.5, screen porosity of 40% and 50%, and gaps of double screens between 1 and 5 cm. The main goal of this study was investigation of the screens creating submerged hydraulic jumps. The flow depth was digitally measured in order to perceive the turbulences and validate the results of energy dissipation against those of the methods in the literature. The experimental results show the importance of each parameter on the screen performance. The screens with double arrangement with the imposed hydraulic jump dissipated more energy. The gaps of the double arrangement had an insignificant effect on energy dissipation. The double screen with porosity of 40% had the best performance. Since the Froude number was found to be the most effective parameter, quadratic equations as a function of this number were fitted to the experimental results with high R$^{2}$ and very low RMSE values. The quadratic equations can be employed as interpolators and/or extrapolators.