Document Type : Research Paper
Authors
1
1- Ph.D. in Hydraulic Structures of Water Sciences, Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
2
Professor, Hydraulic Structures Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3
Department of Hydraulics Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
4
Department of Civil, Environmental and Architectural Engineering, University of L’Aquila, L’Aquila, Italy
Abstract
Stilling basins are energy-dissipating structures that consistently convert flow from a supercritical to a subcritical state. Negative pressure fluctuations cause significant damage in the basin area. Submerged jet injection nearly eliminates the negative pressure effects in supercritical flow, reducing turbulence and flow velocity downstream. This research aimed to investigate the combined effect of a multiple submerged jet system and continuous corrugated roughness on controlling hydraulic jumps in sudden expansion sections. For this purpose, experiments were conducted in a laboratory flume using three combinations of continuous corrugated beds and submerged jet injection systems. The results showed that the hydraulic jump, with three submerged jet discharge rates and within the inlet Froude number range of 6 to 11, reduced fluctuation intensity and water surface variation in the post-expansion section. It also increased energy dissipation. The energy dissipation rate for horizontal submerged jets was, on average, approximately 20 to 25 percent higher than that of classical and discrete jumps. Correspondingly, at a Froude number of 6, the jump length, roller length, and conjugate depths decreased by 50%, 44%, and 63%, respectively, indicating the positive impact of this system on flow stability.
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