Hydrodynamic performance of a hybrid floating breakwater-wave energy conversion system

Abstract

The study presents the hydrodynamic performance and wave energy conversion of a hybrid floating breakwater under the framework of small amplitude linear wave theory. The hybrid floating breakwater is composed of a partially liquid-filled rectangular-box type tank with built-in buoys connected to a Power Take-Off (PTO) (linear inductance generator) and is excited under regular wave conditions for (a) constrained roll motion, and (b) constrained surge, heave, and roll motion. The Boundary Element Method (BEM) is employed with the assumption of modest sloshing in the tank of the hybrid floating breakwater to estimate the hydrodynamic efficiency of the hybrid floating breakwater. Further, the experimental investigation on the Wave Energy Converter (WEC) capabilities and the hydrodynamic coefficients (wave reflection and transmission coefficients) are estimated for the excitation frequencies corresponding to nondimensional wavenumber. The present study reveals that the hybrid concept improves wave attenuation performance by 20%–35% compared to conventional floating breakwaters by increasing wave attenuation, damping and stabilizing the wave transmission coefficient (Formula presented) within (Formula presented). The experimental investigation shows that hybrid floating breakwater attaints its floating stability for the depth 15 – 25% of partially filled fluid for which the proposed design as floating breakwater as well as WEC system is achieved for a wide range of excitation frequencies. Furthermore, the hybrid floating breakwater functions as a barrier which is noted to be capable of significantly attenuating incoming progressive waves below the predetermined threshold values of wave attenuation characteristics, in addition to converting wave energy. © IMechE 2025. This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).