Effects of slope and area opening on the discharge ratio in bottom intake structures

Abstract

The main purpose of this study is to conduct experimental tests on a physical model of bottom intake structures to investigate the effects of slope and area opening of the screen on the amount of diverted discharge. To reach such goals, a bottom intake model was constructed in a flume of 60 cm wide, 8 m long and 60 cm high. The model was tested under different flow discharges, screen slopes and screen open area. Tests were conducted with and without sediment to see the rate of clogging of the screen due to presence of sediment. The results have shown that for small slope the sediment trap between the screen bars which reduce the area opening. Increasing the slope is reducing the sediment to trap but the flow depth over the screen reduces and thus the flow discharge reduces. It was found that at slope of 30%, diverted flow discharge is maximum and at the same time the diverted sediment is minimum. The presence of sediment can reduce 10% the discharge intake. © 2008 Asian Network for Scientific Information.