Comparative performance of a novel oscillating water column wave energy converter

This thesis presents research which shows that a helically configured Oscillating Water Column (OWC) could deliver improved performance compared to a conventional tube OWC, whilst saving a significant amount of draft. It is anticipated that savings in the deployment costs for this compact machine will outweigh any additional manufacturing costs. In order to prove the benefits of the helical concept, its performance relative to a conventional plain tube OWC was investigated in detail using scaled physical models. These models evolved during the course of the study, and refined models were developed. A variable impedance turbine simulator was also developed to test the models at their optimum conditions. The tests themselves were also refined leading to a high degree of confidence in the final result. A mathematical model was also adapted to model the performance of the physical models, and to help understand the physical processes involved in the system. With this series of improving physical models and tests, it has been shown that it is possible to achieve a 27% reduction in draft, with a 24% increase in power output.