Year: 2025
Type: article
Abstract: Hydraulic jumps are essential for dissipating the kinetic energy of high-velocity flows downstream of hydraulic structures such as spillways, drops, chutes, and gates. Effective energy dissipation is critical to prevent scouring and structural damage, and one of the most influential factors in enhancing this dissipation is the roughness of the stilling basin floor. This study investigates how varying bed roughness affects hydraulic jump characteristics in open channel flow. Five-bed conditions were tested, including a smooth surface and four different gravel bed roughness heights: 1.13 cm, 1.58 cm, 2.19 cm, and 2.72 cm. The investigation focused on key hydraulic jump parameters: the sequent depth ratio, relative energy loss, and relative jump length. The results revealed that increasing bed roughness significantly influences jump behavior. Specifically, it was observed that using a roughened bed leads to a marked reduction in both the height and length of the hydraulic jump. Higher initial Froude numbers also increased sequent depth ratios across all bed types. Quantitatively, energy dissipation improved by 7.54%, 21.26%, 25.74%, and 29.27% for the four roughness conditions, respectively, compared to the smooth bed scenario. This improvement in energy loss is accompanied by a considerable reduction in relative sequent depth, ranging from 32% to 66%. Similarly, the relative length of the hydraulic jump decreased by 50% and 29% for the highest roughness levels compared to the smooth condition. These findings confirm that rough beds in stilling basin designs can enhance energy dissipation efficiency while reducing energy dissipaters' spatial requirements and associated construction costs.
DOI: 10.64362/zjse.22
Authors: Shamiran Jargess Shiba, Naeema Thaher Aaref, Shaker A. Jalil
Institution: University of Duhok
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4412347136