Influence of Sill and Artificial Roughness over Adverse Bed Slopes on Hydraulic Jump Characteristics

Hydraulic jump plays a significant role in dissipation of kinetic energy downstream of hydraulic structures in a stilling basin. In the present research, hydraulic jump characteristics on roughened bed with half cylindrical shape bars and rectangular bed sill on two adverse slopes of 1 and 1.5 % and horizontal bed were investigated. In total 338 experiments were performed for Froude numbers ranging from 4.6 to 7.4. The results indicated that the length of the hydraulic jump on the adverse slope of 1.5% decreased 46% with sill and 49% on rough bed. Also maximum reduction of sequent depth on the adverse slope of 1.5 % with sill and on rough bed was 24.4% and 44%, respectively, compared with the classic jump. Furthermore, application of a continuous sill on adverse slope to stabilize hydraulic jump with decreasing its length will be economical.