Three‐dimensional numerical simulations of smooth,asymmetrically roughened,and baffled culverts for upstream passage of small‐bodied fish |
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| Authors: | Gangfu Zhang Hubert Chanson |
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| Affiliation: | 1. School of Civil Engineering, The University of Queensland, Brisbane, Queensland, Australia;2. Resources East, WSP Australia Pty Limited, Brisbane, Queensland, AustraliaPresent address: Gangfu Zhang, Resources East, WSP Australia Pty Limited, Brisbane, QLD 4000, Australia. |
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| Abstract: | Traditional box culvert designs lead to development of high velocity zones in the culvert barrel that often impede upstream migration of fish. Herein, three‐dimensional Reynolds‐averaged Navier‐Stokes (RANS)‐ and Large eddy simulation (LES)‐based computational fluid dynamics (CFDs) simulations were performed to compare the effectiveness of smooth, asymmetrically roughened, and corner‐baffled barrels, in creating low‐velocity zones (LVZs) and providing opportunity for upstream passage of small‐bodied fish. The results revealed distinctive benefits provided by the asymmetrically roughened and corner‐baffled barrels relative to the smooth barrel. Cross‐sectional asymmetry, corners, and obstructions are important factors that contribute to the generation of LVZs conducive to fish passage, albeit contiguity of LVZs is required, particularly for weak swimmers. The study demonstrates the adequacy and effectiveness of CFD models to complement traditional laboratory studies in understanding basic mechanisms beneficial to fish passage and to provide insights into future designs. |
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| Keywords: | box culverts CFD numerical modelling fish passage hydraulic structures low‐velocity zones small‐bodied fish |
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