Hydraulic jump and energy dissipation with stepped weir

• Published in: Journal of water and land development pp. 56 - 61
• Main Authors: Azmeri, Azmeri, Basri, Hairul, Yulianur, Alfiansyah, Ziana, Ziana, Jemi, Faris Zahran, Rahmah, Ridha Aulia
• Format: Journal Article
• Language: English; Polish
• Published: 10.01.2022
• ISSN: 2083-4535; 2083-4535
• DOI: 10.24425/jwld.2021.139015

Energy dissipator functions to dissipate the river-flow energy to avoid longitudinal damage to the downstream river morphology. An optimal energy dissipator planning is essential to fulfilling safe specifications regarding flow behavior. This study aims to determine the variation of energy dissipators and evaluate its effect on the hydraulic jump and energy dissipation. For this purpose, a physical model was carried out on the existing weir condition (two steps). It was also carried out on four stepped-weir variations, i.e., three-step, three-step with additional baffle blocks at the end sills, four-step, and six-step. Dimensional analysis was employed to correlate the different parameters that affect the studied phenomenon. The study shows a three-step jump shows a significantly higher Lj/y1 ratio, which is an advantage to hydraulic jumps’ compaction. The comparison of energy dissipation in all weir variations shows that the three-stepped weir has wasted more energy than other types. The energy dissipation increase of the three-step type is 20.41% higher than the existing type’s energy dissipation and much higher than other types. The dimensions of the energy dissipation basin are the ratio of the width and height of the stairs (l/h) of the three-step type (2.50). Therefore, this type is more optimal to reduce the cavitation risk, which damages the river structure and downstream area.