Investigating the Effect of Horizontal Screen on Hydraulic Parameters of Vertical Drop

Abstract

In the present study, the behavior of hydraulic parameters is investigated for a vertical drop equipped with a horizontal screen. A total of 105 experiments were carried out over a range of parameters, which comprise pool depth, downstream depth, wetted length of the screen, relative mixing length, and energy dissipation with discharge variability of flow for three different drop heights and two porosity ratios. The results indicate that the use of horizontal screens in vertical drops can increase the relative pool depth, the relative downstream depth, and relative energy dissipation compared with a plain vertical drop. It was also found that screens significantly reduce the downstream Froude number from 3.7–6.1 to 0.67–1. A comparison of the porosity of the screens also indicates that the porosity of the screens has an insignificant effect on the performance of the vertical drop. An increase in the porosity of the screens reduces the relative wetted length of horizontal screens and the relative mixing length.