This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different disc...This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different discharges from (6.2 to 18.15) l/s and five different gate cases (vertical and inclined vertically) by angle (45)° with and opposite flow direction with horizontal and sharp lower lip. The values of coefficients of contraction (Cc) and discharge (Cd) increases when gate slope increases with flow direction and the lower lip is horizontal, these increases are (16)% and (18)% respecttively, while these values decreases when gate slope increases opposite flow direction and the lower lip is horizontal these decreases are (13)% and (11)% respectively. The values of coefficient of velocity (Cv) remain constant and don’t effect with changes of gate slope or gate lip.展开更多
The flat fan nozzle with a single orifice formed by a rectangular cut at the nozzle exit through a semi-ellipsoid blind end was developed. The flow rate characteristic of the nozzle was analyzed. Theoretical analysis ...The flat fan nozzle with a single orifice formed by a rectangular cut at the nozzle exit through a semi-ellipsoid blind end was developed. The flow rate characteristic of the nozzle was analyzed. Theoretical analysis shows that the discharge coefficient of the nozzle is a function of the ratio of the projected exit flow area to the cross sectional area of the nozzle input section. Water spraying experiment results show that the discharge coefficient increases with the increase of the ratio of the projected exit flow area to the cross sectional area of the nozzle input section when the rectangular cut depth doesn't exceed the distance from the center of the hemisphere to the nozzle end; conversely,the discharge coefficient decreases with the increase of the ratio; for a given nozzle,the discharge coefficient varies with Reynolds number.展开更多
文摘This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different discharges from (6.2 to 18.15) l/s and five different gate cases (vertical and inclined vertically) by angle (45)° with and opposite flow direction with horizontal and sharp lower lip. The values of coefficients of contraction (Cc) and discharge (Cd) increases when gate slope increases with flow direction and the lower lip is horizontal, these increases are (16)% and (18)% respecttively, while these values decreases when gate slope increases opposite flow direction and the lower lip is horizontal these decreases are (13)% and (11)% respectively. The values of coefficient of velocity (Cv) remain constant and don’t effect with changes of gate slope or gate lip.
基金Science and Technology Program of Shanxi Province,China(No.20120321012)
文摘The flat fan nozzle with a single orifice formed by a rectangular cut at the nozzle exit through a semi-ellipsoid blind end was developed. The flow rate characteristic of the nozzle was analyzed. Theoretical analysis shows that the discharge coefficient of the nozzle is a function of the ratio of the projected exit flow area to the cross sectional area of the nozzle input section. Water spraying experiment results show that the discharge coefficient increases with the increase of the ratio of the projected exit flow area to the cross sectional area of the nozzle input section when the rectangular cut depth doesn't exceed the distance from the center of the hemisphere to the nozzle end; conversely,the discharge coefficient decreases with the increase of the ratio; for a given nozzle,the discharge coefficient varies with Reynolds number.
