Numerical investigations of a pivoted point absorber wave energy converter integrated with breakwater using CFD

Abstract

Wave energy resources are enormous and widely distributed worldwide and evaluated as resources to replace fossil fuels. One of the methods to collect wave energy is using a point absorber device, which is a device designed to react sensitively to the movement of the water surface for harnessing wave energy. This paper is about the influence of a fixed breakwater on a Wavestar-shaped pivoted point absorber wave energy converter (WEC) using computational fluid dynamics (CFD). The fixed breakwater may generate a stationary wave and this phenomenon helps to enlarge the movement of the water surface. The numerical model based on CFD was validated against the available published data and verified to prove the accuracy of the numerical solution. It was found that the present numerical results have a good agreement with the available experimental results. A parametric study was conducted to understand the influence of the fixed breakwater on the WEC. The gap between the fixed breakwater and a buoy of the WEC has been changed according to wave period and the results depending on the gap have been compared. The results suggest a better hydrodynamic performance of the motion responses of the WEC, compared to those without the fixed breakwater. A stationary wave equation considering the gap was derived as a trigonometric function in order to investigate the correlation between a stationary wave and the motion response.