Author(s): Chenjun Zeng; Qiuwen Chen; Li Wang; Yuqin Lin
Linked Author(s): Qiuwen Chen, Chenjun Zeng
Keywords: No Keywords
Abstract: Migratory fishes are usually born in trunk stream and swim back to food-rich lake for feeding during infancy. But the construction of sluice and dam prevents the migrating route of young fish, which leads to the decrease of fish population and thus hurt the health of river ecosystem. This paper considers the influence of sluice and dam to the behavior of juvenile fish migration, setting up a sluice physical model, selects juvenile Ctenopharyngodon idellus and juvenile Mylopharyngodon piceusis as research subjects, study the passing rate, passing time and swim trajectory to pass through the dam under different flow velocity in the gate. This paper presents a computational fluid dynamics (CFD) model able to simulate the three-dimensional (3D) flow within the sluice. The model solves the 3D Reynolds-Averaged Navier-Stokes (RANS) equations, closed with the Standard k-εturbulence formulations. The model employs the volume of fluid (VOF) method to deal with the free surface. Then this paper analyzes the critical hydrodynamic factors that influence fish passing through the sluice from downstream according to the swim trajectory and the hydraulic characteristics. The results show that the juvenile Ctenopharyngodon idellus comparatively have the higher passing rate and shorter passing time than juvenile Mylopharyngodon piceus at the flow velocity ranging from 0.1m/s to 0.5 m/s. The passing rate of juvenile Mylopharyngodon piceus is higher only when the velocity is 0.1 m/s and their passing time are relatively longer under all velocities. The ability of juvenile Ctenopharyngodon idellus to pass through the sluice is better than juvenile Mylopharyngodon piceus and the range of the flow velocity they can adapt to is also wider than that of the later one. In addition, fish prefer to swim at the right side of the study area where the flow velocity and flow velocity gradient are lower. Thus the flow velocity and flow velocity gradient are the crucial hydraulic factors that influence the behavior of fish passing through the sluice.
Year: 2018