Hydrodynamic and energy capture analysis of oscillating water column wave energy converter arrays with shared mooring under concentrated wave action by parabolic breakwater

The energy capture efficiency of oscillating water column (OWC) wave energy converters can be enhanced through the focusing effects of waves by a parabolic breakwater. Additionally, a shared mooring system for positioning the floating device arrays is considered an effective approach to reduce mooring costs. In this paper, a numerical wave tank was established to simulate the hydrodynamic performance of the OWC arrays based on the computational fluid dynamics methods. A mooring numerical model was developed to simulate mooring lines' behavior subject to axial elasticity, hydrodynamic forces, and vertical contact forces with the seabed based on the discrete element method. The numerical model and setup have been validated against experimental results. The motion responses, energy capture performances, and mooring lines' tensions of the floating OWC array under a shared mooring system with and without the parabolic breakwater were compared and analyzed. Results show that the parabolic breakwater significantly enhances the heave and surge motions of the OWC arrays. The central OWC deployed at the theoretical focal point of the parabolic breakwater demonstrates a substantial enhancement in energy capture capacity. Parabolic breakwater leads to an increase in the average mooring force on the leeward side of the OWC arrays system, while reducing the fluctuation in mooring force of the shared polyester ropes. This article can provide favorable reference data for the placement of floating OWC arrays under parabolic breakwater and the design and simulation of the shared mooring system in the future.