In this paper, a numerical wave tank (NWT) based on FLUENT using two-phase VOF model for incompressible viscous flow is presented for the investigation of wave energy converting performance of the Oscillating Water Column (OWC) chamber. The NWT consists of the continuity equation, the Reynolds-averaged Navier-Stokes' equation and the two-phase fractional VOF function. The standard k −ε turbulence model, finite volume method, NITA-PISO algorithm and dynamic mesh technique are employed to generate the 2D and 3D regular incident waves. The oscillating amplitude of water column in the chamber and bi-directional air flow in the duct installed on the top of the chamber are calculated, and compared with experimental data to verify the validation of the present NWT. The nozzle effects of the chamber-duct system on the relative amplitudes of the inner free water surface and air flow rate in the duct are investigated.
Wave energy is one of the most promising forms of ocean renewable sources because of its high energy density. The oscillating water column (OWC) device has been widely employed in the wave energy conversion. It comprises a partially submerged air chamber with an opening in the front skirt, and the water column exposes to the incident wave field through the underwater opening. Waves can force the water column in the chamber to oscillate in the same manner as a simple piston, which will produce the bi-directional air flow through the air turbine in the duct. Capable of operating in the reversing flow conditions, the Wells turbine or the impulse turbine linked to the electric generator in the air duct, is generally used to convert the air static and dynamic pressure into the mechanical energy. The converting efficiency is related to the incident wave conditions and shape parameters of the chamber-duct system.