Effects of air chamber and curtain wall geometries on energy conversion performance in a fixed oscillating water column-type wave energy converter

Abstract

An oscillating water column-type wave energy extractor is composed of an air chamber, an air turbine and a generator. The energy conversion process is compounded of the primary conversion in an air chamber and the secondary conversion of an air turbine. The oscillating water column-type wave energy extractor is considered to be safe even under dirty weather conditions. For societal implementation, there is a need to make a design method which can consider the water surface motion, the pressure fluctuation in an air chamber, the rotations of an air turbine and a generator. At here, the authors carried out the 2-dimensional wave tank tests using the model oscillating water column equipped with the impulse turbine and a generator to obtain the experimental data needed to make this design method. In the experiments, the effects of the air chamber and curtain wall geometries on energy conversion performance in regular wave conditions were investigated. As the results, it is noticed that the geometry of the curtain wall and the vortex shedding from the corners of curtain wall affect the primary conversion efficiency.