Numerical simulation of an OWC-type wave energy converter with projecting walls in regular waves

This paper presents a numerical investigation on the hydrodynamic characteristics of a projecting wall type oscillating water column (OWC) wave energy converter by a frequency-domain linear potential flow model and a CFD model based on Flow3D software. It is found that both the linear potential flow and CFD solutions are in reasonable agreements with the first order experimental results of OWC and air pressure responses. The linear potential solution is found to under-predict the primary-stage energy conversion performance at long wavelengths and the reason may be attributable to nonlinear effects. The airflow velocity response result near the OWC chamber orifice indicates that the nonlinear frequency components are non-negligible. The variation of the velocity magnitude counter near the OWC model is examined based on CFD simulations. The phase differences among the velocities, pressures and OWC response are analyzed, which are expected to be helpful in understanding the physical mechanisms of OWC devices.