Primary Conversion Efficiency of OWC Type WECs Installed on a Large Floating Structure

Abstract

This paper describes the performance of wave power conversion. A large scale floating system on which oscillating water column type wave energy convertors installed is proposed and the efficiency of primary conversion of wave power is estimated. In this paper, a boundary condition due to OWC is theoretically modeled in order to consider influence of wave energy absorption to hydrodynamic forces on the floating structure into the three-dimensional singular point distribution method based on the linear potential theory. In the modeling, a boundary condition on a free water surface and an equation of state within an air-chamber above OWC are mathematically and linearly formulated. Air-pressures and variation of water elevation within OWC areas can be simultaneously and directly solved by setting both the variables and by solving the simultaneously equations of the air-pressure and the vertical displacement. The damper effect of OWC devices is taken into account. The validity of the prediction method proposed is proven by comparing with experimental results. There are three types of large scale wave energy platform which is a pontoon type in the paper. Each performance of the efficiency of primary conversion of wave power is estimated. It is shown that the performance is very good.