Author(s): Zhao Zhou; Yan Liang

Linked Author(s): Zhao Zhou

Keywords: Vertical slot fishway; Velocity field; Three dimensional characteristics; Fish migration

Abstract: In view of the uniform flow field in the conventional vertical slot fishway, there would be no obvious hydraulic differences among the upper, the middle and the bottom layer flow, thus creating reasonable velocity field for only some certain kinds of fish. This paper proposes to dig a surface hole at the top of lateral clapboard to form a combined fishway and then numerically investigates the hydraulic characteristic differences between the conventional vertical slot fishway and the combined fishway. Results show that the mainstream in the conventional vertical slot fishway would move downstream in an S-shaped trajectory with uniform velocity distribution between all layers. The maximum velocity at the vertical slot region can generally be as much as 1.3m/s with maximum turbulent kinetic energy to be 0.124m2/s2 in the typical conditions. But in view of the large discharge by the surface hole, the mainstream in the combined fishway would branch into two strands with quite typical three dimensional flow field, thus forming a unique large span velocity field. The maximum velocity at the surface hole and vertical slot region can respectively be 1.3m/s and 0.8m/s. Such unique velocity field in the combined fishway can provide more conveniences for more kinds of fish migration.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022714

Year: 2022