Time evolution effect on the scour characteristics downstream of the sluice gate with the submerged hydraulic jump in a laboratory model

Sluice gates are utilized in dams and irrigation channels as regulating structures in the channel have the role of regulating the water level for proper water intake of upstream intakes. As high velocity and energy of the flow issuing from these hydraulic structures scour occurred in erodible downstream beds. Occurrence of the hydraulic jump is very possible, and when it forms, therefore the necessity of investigating the flow condition increases. The scouring phenomenon is a time evolution and a long-time procedure. This research focused on time effects on experimental data received by a sediment bed profiler at different times from the experimental setup conducted in a laboratory. The maximum scour depth (dse), the maximum dune height (hd), the horizontal distance of the maximum scour depth from the beginning of the sedimentary bed (xse), and the horizontal distance of the maximum dune height from the beginning of the sedimentary bed (xd) were investigated. Laboratory observations show that the extension of the location of the maximum scour depth and the maximum height of the dune formed with time is evident. The laboratory data for the dimensionless conditions of 4 scour profiles characteristics including dse/b0, hd/b0, xse/b0, and xd/b0 were analyzed by the nonlinear regression method, and separate equations were proposed for each characteristic. RMSE=0.045, 0.0677, 0.358, and 2.146 respectively, and the R2 =0.996, 0.975, 0.974, and 0.977 respectively.