ABSTRACT
A computational study of hydrokinetic turbine hydrodynamics by using a hybrid viscous/inviscid–flow model is presented. The methodology integrates Detached Eddy Simulation for the numerical solution of the Navier-Stokes equations with a Boundary Integral Equation Model for potential flows. The formulation generalizes standard actuator disc models and provides a computationally efficient model to analyse the hydrodynamic performance and flow field of single turbines and arrays in a viscous turbulent onset flow. An application of the hybrid DES/BIEM model to the analysis of the wake field downstream a horizontal-axis turbine in uniform flow is presented. Numerical results for a five-bladed bi-directional turbine with elliptical blade sections are compared with experimental results including performance curves and a detailed characterization of the flow field downstream the rotor using Particle Image Velocimetry. Results demonstrate the capability of the proposed methodology to correctly describe main flow features characterizing the turbine wake.
