Abstract
Hydraulic jumps are a fundamental phenomenon in open channel hydraulics, playing a critical role in energy dissipation and stilling basin design. Experimental research was conducted to investigate the hydraulic jump controlled with a thin-crested sill of varying heights and positions, which has not been previously investigated. Therefore, this experimental study was conducted to investigate hydraulic jump control using a thin-crested sill of varying heights and positions. The exact location of the hydraulic jump within the horizontal open channel should be known to prevent any damage to the surrounding structures. In total, 130 experiments were performed with initial Froude numbers ranging from 3.42 to 8.93. Measurements included the basic variables, such as initial and sequential depths, jump lengths, energy losses for sluice gate openings, and different discharge rates. Findings indicate that although the sill placement had minimal effect on the sequent depth ratio, it had a significant reduction in jump length, jump position, and energy dissipation in the stilling basin. The experimental sequent depth ratio (y₂/y₁) showed close agreement with the values predicted by Bélanger's equation. In addition, regression models developed to estimate the sequent depth ratio, jump length, energy loss, and optimal sill location achieved coefficients of determination ranging from 0.82 to 0.98. These results provide practical design guidance for selecting appropriate sill dimensions and locations to ensure complete hydraulic jump formation and effective energy dissipation in stilling basins.