Experimental Study of Energy Dissipation in the Stilling Basin with Movable Bed in the Upstream of Screens

Screens are lattice plates with certain porosity arranged vertically in the supercritical flow inducing energy dissipation and hydraulic jump stabilization. In this study, energy dissipation due to Hydraulic jump and Screens are investigated experimentally. The main variables of the study are: (i) the Froude number of supercritical flow (FrA) in the 3.5-8 range; (ii) five samples of bed grains with a median diameter of 4.1-24 mm; (iii) screen with 40% and 50% porosities. The results from the study clarified change energy dissipation pit against supercritical Froude number, the participation of Screen and hydraulic jump in energy dissipation and the effect of porosity on energy dissipation. Also, to calculate the energy dissipation in the downstream of the Screen, some relationships have been presented and the results have been compared with previous studies. The results showed that the Froude number (FrA) of supercritical flow have a great effect on energy depreciation. Also, the effect of dimensionless grain sizes (d50) and maximum scour depth (Ds) is negligible on energy depreciation.