Fluid-structure interaction modelling of vortex-induced motion energy converter (VIMEC). A computational fluid dynamics approach.

Abstract

Innovative hydrokinetic energy harvesting devices appear as environmentally friendly alternatives to traditional energy sources, particularly concepts based on exploiting flow phenomena of vortex-induced vibrations (VIV) and galloping. The present thesis explores a novel vortex-induced motion energy converter (VIMEC) designed to efficiently convert the kinetic energy contained in a current flow into electricity. The methodology employed in the study relies on numerical modeling and experimental verification. The numerical model of the Fluid-Structure Interaction (FSI) phenomena is developed in the open-source Computational Fluid Dynamics (CFD) framework OpenFOAM. The numerical model, replicating an experimental setup tested in SINTEF Ocean's towing tank, was validated for both open-water and near-wall scenarios. The study found that being close to a wall has an insignificant impact on the VIMEC performance, confirming its suitability for seabed deployment. Detailed analysis identified the best damping configuration for maximum power output. Economically, the device proved viable in various challenging scenarios, with levelized cost of energy (LCOE) calculations showing it competitive with other renewable energy sources. The findings demonstrate the VIMEC's potential to be a viable option for renewable energy generation for remote locations with access to flowing water, such as coastal areas and rivers.