Virtual fish concept: Numerical prediction of fish passage through hydraulic powerplants

This paper presents a brief overview of the latest developments in the area of numerical simulation of fish passage through hydropower installations. An advanced Computational Fluid Dynamics (CFD) method has been developed for simulating complex hydroturbine flows. The output of this method provides the virtual flow environment through which the motion of `virtual' fish is investigated. This is accomplished by using a novel fish passage model for tracking the trajectories of three-dimensional fish-like bodies through the precomputed flow field. The model yields detailed quantitative information about forces acting locally on the fish body, potential for scraping and descaling, dizziness effects, and other sources which could cause injury and/or mortality. The potential of the proposed approach is demonstrated by applying it to track fish trajectories through TVA's Norris Dam draft tube.