摘要：A numerical study of the free surface flow on an ogee-crested fish bypass is
presented. The geometry corresponds to a juvenile fish bypass proposed for
Wanapum Dam, on the Columbia River, State of Washington. A free-surface
numerical model which solves the RANS equations coupled to a surface-capturing
algorithm to predict the flow in air and water was developed using the volume of
fluid (VOF) method with the commercial CFD code Fluent 6.1. The k epsilon-µ
model of turbulence with wall functions was used to compute the eddy viscosity.
Structured/unstructured hybrid grids were used to accommodate the complex
geometry that included gate slots, flow control gates, and an aeration slot. The
tailrace performance curves were reproduced numerically, predicting the
plunging, skimming or surface ramp regimes resulting from different tailrace
elevations. Free surface elevations, pressure along the ogee surface, and
discharge rating curves were compared against the experimental data from the
laboratory model for different headwater elevations and gate settings. Once
deemed reliable through validation against experimental data, the computational
model was used to analyze the flow field, supplementing the areas of limited
experimental data. Predicted numerical model results included pressure and
velocity distributions and free-surface configurations that helped analyze
cavitation potential and flow performance of the spillway. Future analysis may
link the hydrodynamic results with an existing fish behavioral model
