Array of concentric perforated cylindrical systems with torus oscillating bodies integrated on inner cylinders

Abstract

In this study, a theoretical method was proposed to investigate the linear wave interactions with a square array of hybrid wave energy extraction (HWEE) systems, each constructed by integrating a torus oscillating buoy on a bottom-mounted concentric perforated cylindrical system. The method of variable separation and eigenfunction expansion matching were employed to solve the diffraction and radiation problems. The model was validated against published results. First, the effects of the incident wave angle and distance between two HWEE systems in one column or row on the hydrodynamic performances of the HWEE system array, were investigated without considering the outer cylinders. Subsequently, the effects of arranging arc-shaped perforated cylinders with different porosities, radii, and covering angles around the HWEE system array were investigated. The wave energy extraction performance of the HWEE system array and horizontal wave forces on the inner cylinders were determined as primary concerns. It was found that when incident waves propagate along the side and diagonal of the square array, there exist frequency regions wherein the wave energy extraction efficiency and the wave forces on the inner cylinders were both positively affected by the interactions among the HWEE system array. When the arc-shaped outer cylinders were impermeable, wave energy extraction was significantly improved.