Author(s): C. S. Lauchlan Arrowsmith; Y. Zhu

Linked Author(s): Yumeng Zhu

Keywords: Fishway; Hydraulic modelling; Turbulence; CFD modelling

Abstract: The performance of a fishway is heavily dependent on the interplay between the hydraulic properties of the structure and adjacent waterway, and the biological variables of the targeted fish species. The optimal parameters for a vertical slot fishway such as the step height and opening size are usually difficult to obtain. To date Water Technology have utilised a 2D hydraulic modelling tool (MIKE21) to understand and design these structures. The limitation of this 2D modelling approach is the assumption of a uniform vertical velocity distribution and at fine grid scales inconsistencies in velocity and turbulence estimates provided by such models have been noted. To improve the ability to resolve fine scale velocity distributions and turbulence structures to the level required for fishway design the fully 3D modelling hydrodynamic package ANSYS CFX was used to model an existing fishway design. This allowed enhanced resolution and therefore understanding of the velocity distribution and turbulence structure within the fishway and provided a direct comparison between the 2D and 3D approaches. Based on the outcomes of this assessment a generalised design approach has been developed for vertical slot fishways, which will improve the understanding of the hydraulic properties of each structure, and the adjacent waterway and improve our ability to meet the specific requirements of Australian fish species.

DOI: https://doi.org/10.14264/uql.2014.49

Year: 2014