Numerical and experimental study of a heaving buoy for modelling a wave energy converter for WECfarm project

Waves from Ocean are a huge unexploited energy resource, and the potential for extracting energy from waves is significant. Oceanic surface waves carry a much higher energy density, sometimes by two orders of magnitude, than solar and wind. For this reason, different Wave Energy Converter (WEC) designs have been developed in recent years. Among all the technologies available to convert wave energy, the point-absorber is one of the most promising solutions today, due to its ease of both fabrication and installation. In most cases, the WEC will not be installed in single units but arranged in parks to extract an important amount of wave power. In the former WECwakes project, a number of 25 WEC buoys were arranged in different geometric configurations and tested to several wave conditions. Each WEC was composed of a hemispherical ended cylindrical buoy designed to heave only. Essential data was obtained about the importance of WEC array effects. Nevertheless, improvement of the understanding regarding the WEC array effects by providing high quality experimental data is desired. Therefore, the WECfarm project was established. A first target in the progress is to improve the original WEC design.The main aim of this master dissertation was to validate the improved features of a new-shape WEC design to increase radiation effect and to maximize the wave-WEC interactions, the WEC-WEC interactions and to reduce surge force on the WEC structure. By means of a Boundary Element Method model (Nemoh) included in openWEC, an easy-to-use WEC simulation tool, a numerical study was performed to evaluate the performance of the designed WEC unit. A solution is obtained which allows to predict the device behaviour in regular waves. At the end, a validation of the model is carried out via experimental studies in the wave flume of Coastal Engineering Research Group of Ghent University to evaluate the numerical results of the WEC unit.