Numerical Modeling of the Effect of Changing the Geometry of Fishway Structure on the Flow-Through Its Vertical Slot

In the present study, hydraulics of vertical slot is simulated, using Flow-3D. k-ε turbulence model had the most performance among different turbulence models. Next, the velocity pattern, volume of fish rest-area, and flow turbulence in the channel were analyzed in order to evaluate the performance of fishway with different geometries. In this regard, the influence of geometry on the performance of fishway is investigated. Results showed that by decreasing the ratio of the length of the large wall to the small wall, the longitudinal component of velocity was decreased by an average of 25.11%. By increasing the end of the large-wall angle with respect to the pool wall, the volume of the rest area was increased by 3%. By increasing the end of the large-wall angle with respect to the pool wall parameter, the turbulence energy was increased by an average of 30.66%. In general, the ratio of the length of the large wall to the small wall has a greater effect on reducing the flow velocity for the fish to cross the fishway and also by increasing the end of the large-wall angle with respect to the pool wall, the rest area of the fish and turbulence energy has increased.