Experimental Evaluation of Hydraulic Jump Characteristics in Gradually Expanding Sloping Channel

Understanding hydraulic jumps in gradually expanding sloping channels is crucial for designing eco-friendly water management systems that minimize environmental impacts. This study seeks to investigate how the expansion ratio and channel slope together influence the characteristics of hydraulic jumps. The experiments were performed on four different channel slopes (00, 20, 40, and 60) and four distinct expansion ratios (B = b1/b2) of 0.35, 0.45, 0.55 and 0.75. The Reynolds number was ranged from 7150 to 27750, while the Froude number varied between 2.5 and 8.5 during the experiments. Novel correlations were developed to predict key hydraulic jump parameters, including depth ratio (d₂/d₁), relative energy loss (EL/E₁) and relative jump length (Lj/d₁), by considering the effects of expansion ratio, channel slope and Froude number. The results indicate that as the channel slope increased from 0° to 6°, the depth ratio and relative energy loss increased by approximately30.53% and 15.37%, respectively, while the relative jump length decreased by 11.11%. Conversely, as the expansion ratio decreased from 1.0 to 0.35, the depth ratio and relative jump length were reduced by approximately 9.63% and 10.42%, respectively; while the relative energy loss was increased by 24.21%.These findings highlight the significant influence of channel geometry on hydraulic jump characteristics, offering valuable insights for optimizing water conveyance structures. The proposed correlations provide a novel and intuitive approach to analyze hydraulic jumps in expanding sloping channels, addressing gaps in existing literature and contributing to sustainable water resource management.