عنوان مقاله [English]
In this study, the effects of suction tube inlet opening shape on sediment discharge efficiency of dams reservoirs were investigated. For achieving this purpose, several experiments were carried out using different shapes of the suction tubing opening, including the plain-type and wedge in the middle of suction mouth. The wedge type was considered with four angles of the pipe opening relative to the tube stretch (α =15, 30, 45 and 60 degrees). Experiment were conducted at three levels of tube mouth placement (Hp) at HP=+2 cm, 0 cm and -2 cm based on the sediment surface. The results of the experiments showed that with increasing the ratio of H_p/D_p (Dp is the pipe diameter), the volume of sediment removal (Λ) decreases. Also, at α = 15o and 30o, the ratio of Λ/〖D_p〗^3 was decreased in comparison with the control test (plain-type, α = 90°), while at α = 60° value of Λ/〖D_p〗^3 was increased. Also, the results of the experiments showed that with the assumption of a constant H_p/D_p ratio and by increasing the amount of α, the ratio of Λ/〖D_p〗^3 and the concentration of the sediment outflow would be enhanced. Assuming that the ratio of H_p/D_p is constant, solely at α = 60°, the value of Λ/〖D_p〗^3 was increased compared to the control test. In brief, findings of this study reveal that using a wedge shape inlet suction mouth with α = 60° and digging it through the sediment will lead to a better performance of the hydrosuction system.