Dynamic Response of a Combined Mono-Pile Wind Turbine and Heave-Type Wave Energy Converter System

In present work, a novel concept by combing a monopile wind turbine and a heave-type wave energy converter has been proposed, that is referred as the ‘MWWC’ (Mono-WT-WEC Combination) system herein. Concept feasibility study has been carried out by doing coupled aerodynamic and hydrodynamic numerical simulation in the time domain. Aerodynamic loads and output wind power of the NREL 5MW wind turbine are determined by the NREL Aerodyn code, based on BEM method. Hydrodynamic loads of the mono-pile and the WEC are calculated by the AQWA code, which is available for modeling multi-body systems including both mechanical and hydrodynamic couplings between the mono-pile and the WEC. Firstly, the effect of different power-take-off (PTO) parameters and wave periods on the performance of the WEC’s wave energy production under typical wave cases has been investigate, and a preliminary optimal value for the PTO’s damping stiffness has been proposed; secondly, the dynamic characteristic of the MWWC system has been investigate using coupled wind-wave loads analysis under typical operational sea cases. Finally, the extreme responses of the MWWC system have been obtained for its ULS design, and the potential challenging areas of the MWWC system has been highlighted.