Author(s): Seyed Sobhan Aleyasin; Xingjun Fang; Mark Francis Tachie; Christos Katopodis; Haitham Ghamry
Linked Author(s): Christos Katopodis
Keywords: No Keywords
Abstract: The flow field in the bypass of a bar rack system is studied using particle image velocimetry systems, focusing on the effects of the weir installed at the bypass entrance on the hydraulic conditions that influence the movement of fish downstream toward the bypass. The test cases are (a) no weir, (b) triangular weir and (c) arch-shaped weir to investigate suitable hydraulics for various species. Mean velocities, spatial acceleration, Reynolds stresses, turbulent kinetic energy and turbulent eddies are analyzed. It is observed that the weirs deflect the flow away from the channel bed and increase the bypass velocity significantly, though does not surpass the critical value of 1 m/s, above which juvenile Atlantic salmon tend to avoid using burst swimming. The Reynolds stresses and turbulent kinetic energy (TKE) exhibit elevated values in the vicinity of the weirs and the shear layers issuing from the weir tips. However, TKE remains in the most suitable range for fish such as rainbow trout. Also, the eddy topology is modified by the weir in such a way as to support fish movement toward the bypass.
Year: 2024