Bonneville Tailrace Project: Three-Dimensional CFD Models and Flow Measurements
PNNL research scientists developed computational fluid dynamic models (STAR-CD and FLOW-3D) capable of simulating the three-dimensional velocity field downstream of the Bonneville Project. These models were tested and verified against laboratory (1:100 and 1:30 scale physical models) and field acoustic doppler current profilers (ADCP) measurements. Once verification of these models was complete, structural alternatives were simulated in the model by locating a high-flow outfall in multiple tailrace locations. The models were then used to predict differences in water circulation patterns between current conditions and proposed alternatives. Alternatives simulated to date have primarily focused on the optimal location of a high-flow outfall that may be used to increase survival of downstream migrant smolt. The numerical mesh was developed using GRIDGEN, ARC/INFO and STAR-CD based upon bathymetric surveys and engineering drawing of the physical structures.