Numerical study of the effect of a V‐shaped weir on turbulence characteristics and velocity in V‐weir fishways. (14th October 2022)

• Record Type: Journal Article
• Authors: Shahabi, Maryam; Ahadiyan, Javad; Ghomeshi, Mehdi; Narimousa, Marjan; Katopodis, Christos; Azizi Nadian, Hossein
• Is Part Of: River research and applications. Volume 39:Number 1(2023)
• Page Start: 21
• Page End: 34
• Publication Date: 2022-10-14
• Subjects: fishway -- Reynolds shear stress -- turbulent dissipation -- turbulent intensity -- turbulent kinetic energy; Rivers -- Regulation -- Periodicals; Rivers -- Periodicals; 551.483
• DOI: 10.1002/rra.4064
• Languages: English
• ISSNs: 1535-1459

Abstract

Abstract: Fishways are used to allow fish to migrate around water infrastructure, whether movements are in the upstream or downstream direction. Hydrodynamic conditions within various fishways, including turbulence levels, are important for successful fish passage. A numerical hydrodynamic study was conducted for V‐weir fishways, which assist species migrating upstream. The variables investigated included, fishway slopes of 4%, 7%, and 10%, relative spacing between weirs of 1.3, 2.6, and 4 (D/L, ratio of distance between weirs to pool width), and weir angles of 22.5°, 40°, and 60°. Turbulence characteristics, including turbulent kinetic energy (TKE), Reynolds shear stress (RSS), turbulent intensity (TI), turbulent dissipation (TD), as well as maximum water velocity, were examined by CFD (computational fluid dynamics) simulation using a re‐normalized group or RNG turbulence model. The CFD was calibrated with flow measurements made in a physical model of the V‐weir fishway in laboratory control experiments. Based on inferences from fish passage literature, the results showed that, in the range of parameters studied, a weir angle of 22.5 °, a slope of 10% and relative spacing between weirs of 1.3 and 2.6 were assessed as offering the best potential performance for several species and sizes of fish, while the latter has lower cost as it requires fewer weirs. The V‐weir fishway may be adaptable for smaller fish.