Development of a viscous/Inviscid Hydrodynammics Model for Single Turbines and Arrays

A computational model for the hydrodynamic analysis of current turbines is presented. The methodology integrates a Boundary Integral Equation Model (BIEM) for inviscid flows and a Navier-Stokes solver to obtain a computationally efficient tool for the analysis of single turbine performance and wakes as well as turbine-turbine interaction in tidal arrays. The resulting hybrid viscous/inviscid formulation generalizes standard actuator disc models and is valid under arbitrary unsteady, non-uniform onset flow conditions. A simple viscous-flow correction model is combined with BIEM to account for the effects of separation and stall on blade loads. Numerical applications address single turbine performance by BIEM, single turbine wakefield analysis by hybrid RANS/BIEM and turbine-turbine interaction by hybrid RANS/BIEM. Numerical results are validated against experimental data.