Wave power absorption of semi-circular oscillating water column arrays mounted on a straight coastal structure

Abstract

Grouping wave energy converters to form an array, also known as a wave-farm, enhances their energy absorption performance. A cost-effective strategy is to install multiple wave energy converters along a coastal structure, such as a breakwater or seawall. Not only does this reduce construction costs, but it also improves energy absorption, as waves are reflected towards the wave energy converters by the structure. In this paper, the hydrodynamic response of an array of semi-circular oscillating water columns mounted on a straight coastal structure is investigated. By applying linear potential flow theory and an eigenfunction-matching formulation, an analytical solution is derived to evaluate the wave excitation, wave radiation coefficients, wave power absorption, and wave forces on the oscillating water column chambers. Having confirmed the reliability of the model through comparison with previous research, parametric analyses are conducted. The overall hydrodynamic performance and wave forces depend significantly on the array configuration and the incident wave direction. It is important to note that significant interference effects are observed between the oscillating water column chambers of the array, which can either enhance or reduce power output. These findings provide some insight into the design and optimization of multi-chamber oscillating water column systems.