A numerical performance analysis of a ducted, high-solidity tidal turbine

Abstract

This study puts forward an investigation into the hydrodynamic performance concerning a ducted, high-solidity tidal turbine utilising blade-resolved computational fluid dynamics. The model achieves similarity values of over 0.96 with experimentation data regarding a three-bladed horizontal-axis tidal turbine in validation of three distinct parameters: power & torque coefficient, thrust coefficient, and wake velocity profiles. Accordingly, the model was employed for the analysis of a ducted, high-solidity turbine in axially-aligned flows at distinct free-stream velocities. The resultant hydrodynamic performance characteristics portrayed a peak power coefficient of 0.34, with a thrust coefficient of 0.97, at a nominal tip-speed ratio of 1.75. Coefficient trend agreement was attained between the numerical model and experimentation data established in literature and blade-element momentum theory; the model furthers the analysis by elaborating the temporal hydrodynamic features induced by the fluid-structure interaction in specification to the wake formation velocity profiles, pressure distribution along the blades and duct, mass flow rate, and vortex shedding effects to establish the characteristic flow physics of the tidal turbine.