Performance of an array of oscillating water column devices integrated with an offshore detached breakwater

Abstract

A systematic experimental investigation on the effect of different spacing between an array of oscillating water column (OWC) devices integrated with offshore detached breakwater (ODBW) in terms of their hydrodynamic performance has been studied. A Froude scale of 1:20 was chosen for integrating five similar devices of OWC to the ODBW (OWCBW) and a series of experiments was carried out in a shallow wave basin. Three different centre to centre spacings, S, i.e., one, two, and three times the width of the OWC model were considered. The hydrodynamic performance was studied in terms of non-dimensional lip wall pressure, wave amplification factor, non-dimensional air pressure, capture width, and relative capture width. The OWCBW system with thrice the width of the model spacing exhibits a better performance. The convergence of water waves in front of the OWC devices due to obstruction from rubble mound breakwaters to progressive waves enhances the concentration of energy in front of the array of OWC devices. It facilitates the system to absorb a larger amount of wave power of about 2.2 times the given input power at natural frequency of the system. This confirms that the array of OWC devices exhibits better performance than in isolation.