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Abstract: Upstream migration of fish through circular culverts is often prevented by velocities in the barrel being higher than that of the natural channel. In this investigation a computational fluid dynamic (CFD) model has been used to test the effects of various spoiler baffle geometries in culverts of varying size to reduce water velocity and increase water depth and thus increase the upstream passage of small fish species. Results indicated that standard baffles designed for specific fish species or groups could be successfully retrofitted to culverts of varying dimensions. Subsequent field tests have confirmed the effectiveness of the design. [Copyright &y& Elsevier]

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Although waterway connectivity is a requirement for all freshwater fish, culverts have had negative impacts on freshwater river ecology. Following a recent biological study suggesting that asymmetrical wall baffles may be conducive to upstream passage of small-bodied fish, experimental modeling of plain wall baffles on one sidewall only was conducted under controlled flow conditions. The measurements were performed in a 15-m-long, 0.5-m-wide culvert barrel channel at several longitudinal and transverse locations for a broad range of discharges and baffle geometries to deliver a fine characterization of the hydrodynamics of the asymmetrically baffled channel. The physical modeling data illustrated the drastic impact of a seemingly simple boundary treatment (i.e., plain rectangular baffles) on the flow field. In practice, the installation of baffles has practical engineering implications that must not be ignored. [ABSTRACT FROM AUTHOR]

This paper presents the findings of a study into how different inlet designs for stormwater culverts increase the discharge rate. The objective of the study was to develop improved inlet designs that could be retro-fitted to existing stormwater culvert structures in order to increase discharge capacity and allow for changing rainfall patterns and severe weather events that are expected as a consequence of climate change. Three different chamfer angles and a rounded corner were simulated with the software ANSYS Fluent, each of the shapes tested in five different sizes. Rounded and 45 ∘ chamfers at the inlet edge performed best, significantly increasing the flow rate, though the size of the configurations was a critical factor. Inlet angles of 30 ∘ and 60 ∘ caused greater turbulence in the simulations than did 45 ∘ and the rounded corner. The best performing shape of the inlet, the rounded corner, was tested in an experimental flume. The flume flow experiment showed that the optimal inlet configuration, a rounded inlet (radius = 1/5 culvert width) improved the flow rate by up to 20% under submerged inlet control conditions. [ABSTRACT FROM AUTHOR]