Experimental Investigation of an Annular Sector OWC Device Incorporated into a Dual Cylindrical Caisson Breakwater

Abstract The annular sector Oscillating Water Column (AS-OWC) device incorporated into a dual cylindrical caisson breakwater is proposed and the hydrodynamic performance is investigated experimentally. The free surface elevations inside and outside the water chamber are measured, as well as the air pressure both in the air chamber and the air duct. In order to overcome the influence induced by the uneven free surface in the chamber with a complicated geometry, the pressure method is proposed and applied to calculate the airflow rate through the air duct instead of the traditional water level method. The pneumatic damping characteristics and the hydrodynamic performance of the proposed AS-OWC integrated device are analyzed under different wave conditions. Experimental results indicate that the maximum hydrodynamic efficiency of the developed wave energy conversion device can be reached up to 81% within the present experimental range.