Semi-analytical study on the hydrodynamic performance of an integrated wave energy extraction system consisting of a heaving buoy over a sill and a Jarlan-type breakwater

A study was conducted on an integrated wave energy extraction (IWEE) system, which includes a heaving wave energy converter (WEC) and a Jarlan-type breakwater, using the linear potential flow theory for analysis. The methods of variable separation and eigenfunction expansion matching were utilized to calculate the velocity potentials in space. Following theoretical and numerical validation, the IWEE system model was compared with existing models, and parametric studies of its hydrodynamic performance and energy capture capabilities were conducted. Subsequently, the wave loads on the system were calculated for safety and reliability design. Results indicate that integrating a Jarlan-type breakwater downstream of the buoy significantly enhances the device's energy capture efficiency and wave dissipation performance compared to an isolated WEC. The presence of a perforated plate can effectively suppress the considerable wave force caused by the wall reflections. The wave attenuation performance and energy capture capability could be improved by correctly adjusting the geometrical parameters. Additionally, the comparison results of the wave forces indicate that the IWEE system is benefited of larger wave forces which can perform better wave dissipation and wave power extraction, thus a compromise analysis between power conversion performance and reliability of the hybrid system is needed for appliance.