Session B5: 2D Modelling of Nature-Like Fish Passes

Abstract: The passability of nature-like fishpass depends on water depth, velocity and kinetic turbulent energy. To estimate these values the 2D Saint Venant code can be an interesting tool because it can simulate a large range of geometrical configuration and also take into account the deformation of the free surface. However the flow in a fish pass can reach the limit of the model assumptions as the hydrostatic pressure. As a consequence a series of experiments on down-scale are conducted to validate the numerical results. Velocity and turbulent fields are measured by Acoustic Doppler Velocimeter (ADV) for five combinations of discharge and slope. The comparison between experiments and model shows that the numerical results are relevant for a moderate Froude number which corresponds to fishpass application. Moreover, some crucial data related to passability are extracted from the computation as the maximum velocity location