Journal of Hydraulic Structures

Journal of Hydraulic Structures

Hydraulic performance of stepped spillways with reverse step barriers under skimming flow conditions: a three-dimensional numerical study

Articles in Press

Document Type : Research Paper

Authors
Dana Ghaderi 1
Hamzeh Ebrahimnezhadian 2
Mahdi Mollazadeh 1
1 Department of Civil Engineering, University of Birjand, Birjand, Iran.
2 Department of hydraulic structures, Urmia, Iran.
10.22055/jhs.2026.51891.1379
Abstract
In recent years, the application of stepped spillways has increased owing to their high efficiency. Therefore, studies in this field have been of interest to researchers. Most of the studies have been focused on improving the ability of energy dissipation. In this research, a special configuration was presented named stepped spillway with reverse step barriers, and its energy dissipation capability was evaluated in comparison with conventional stepped spillways. The numerical model was validated against experimental results obtained from the physical model. OpenFOAM was used to develop five three-dimensional reverse step barrier configurations designed for skimming flow. The flow was simulated using the InterFoam solver with the RNG k–ε turbulence model. The findings reveal a substantial enhancement in energy dissipation toward the downstream section of the spillway. Also, among the different configurations, G2 geometry exhibited the highest energy dissipation rate. At a discharge of 0.09 m³/s and a yc/h ratio of 1.45, the G2–G5 configurations achieved greater energy dissipation than the conventional stepped spillway, with increases of 64.1%, 26.4%, 41.5%, and 54.7% for G2, G3, G4, and G5, respectively. Finally, G2 geometry was proposed as the best-performing configuration in stepped spillways with reverse step barriers in terms of energy dissipation rate.
Keywords
Stepped spillway
Computational fluid dynamics
OpenFOAM software
Energy dissipation
Reverse step barriers
Subjects
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Journal of Hydraulic Structures

Articles in Press, Accepted Manuscript
Available Online from 13 September 2026