Experimental Investigation of Submerged Hydraulic JumpDownstream of Sluice Gate in Erodible Channel

Sluice gates are widely applied in regulating and distributing the water flow inirrigation erodible channels. Hence their downstream hydraulic conditions maycause a critical flow, which could be generated a hydraulic jump. In this research,the formation of the submerged hydraulic jump and the characteristics of theflow downstream of the sluice gate in the channel with the sand bed areinvestigated in the laboratory. For this purpose, tests were performed on a ۳۰ cmwide sluice gate with three gate opening gates (b۰= ۱.۵, ۲, and ۲.۵ cm) forFr=۱.۴۷ to ۴.۸۲. A rigid apron with a length of ۱.۵ meters is used to stabilize thebed, where the jump is formed. The mean velocity distributions (U/Um) with y/y۱were investigated at three longitudinal positions including Pa: ۰.۵ m after thegate opening, Pb: the beginning of the sedimentary bed, and Pc: the end of it. Theresults show that the mean velocity at the end of the sedimentary bed is onaverage about ۱۸% lower than at the beginning of it. Also, it was indicated thatthe Froude number and the tailwater depth are important parameters in designingthe sluice gate of the erodible irrigation channel.