Experimental study of the hydrodynamic characteristics of an inclined OWC wave energy converter integrated with a fore-reef slope

Coral reef islands, traditionally characterized by intense wave action on their fore-reef slopes due to steep bathymetry and drastic wave shoaling, present a unique energy prospect. The high wave energy density in these regions could potentially augment the renewable energy portfolio for facilities on these islands. This study proposes a fore-reef-integrated oscillating water column intended for wave energy capturing and clean energy production in coral reef island scenarios, featuring a rectangular inclined chamber installed on the fore-reef of a reef island. The hydrodynamic performance of the device was tested in a wave flume under moderate sea conditions. Measurements included air pressure, water surface elevation, and wave energy dynamics (e.g., absorption, reflection, and dissipation of wave energy). The study found that lower tides broaden the high-efficiency frequency range, while higher wave heights stabilize efficiency near the resonant frequency. Furthermore, the study investigated nonlinear responses within the chamber, with results highlighting the presence of wave-induced setup inside the pneumatic chamber due to breaking waves. This setup was closely associated with pressure skewness and second-order heave motion within the chamber. Overall, these insights contribute to advancing our understanding of wave energy technology’s potential applications in reef island environments.