Experimental Investigation of the Performance of Horizontal Screen on Energy Dissipation in Inclined Drop

In the present study, horizontal screens at brink of inclined drop were used as an energy dissipater structure to increase the downstream energy dissipation. The experiments were carried out in three angles of drop, two drop heights, and two porosity ratios of horizontal screen. In total, 108 experiments were performed in discharge range of 200–700 L/min. The results showed that the energy dissipation increases with increasing relative wetting length of the screen, such a way that the highest energy dissipation occurs in the horizontal screen with a porosity of 40%. Inclined drop equipped with horizontal screen reduced downstream Froude numbers in three angles of drop and two porosity ratios from a range of 4.49 - 8.35 to a range of 1.48 - 5.78. Also, increasing the angle of drop increases the relative depth of downstream, so that the drop angle of 45 ° and screen porosity of 40% had the best performance in increasing the relative depth of downstream. Increasing the drop angle and screen porosity also reduces the average efficiency of energy dissipation.