Abstract
Offshore wind turbines play a key role in renewable energy strategies due to higher power generation in offshore areas. As the development of offshore wind turbines (OWT) moves from near-coastal areas to the deep sea, a floating-type foundation is the inevitable direction. The hydrodynamic performance analysis of floating offshore wind turbines (FOWT) is required under different marine conditions to improve the structure's safety and stability and ensure power generation efficiency. However, the study of extreme wave condition interaction with FOWT, like tsunami waves, incidental rogue waves, etc., remains a difficult scientific research challenge. In this paper, the hydrodynamic performance of a Semi-submersible platform of FOWT is modelled and analyzed under extreme waves using the Hydrodynamic-Coupling (HDC) method. The HDC framework couples the fully nonlinear potential flow (FNPF) solver and Computational fluid dynamics (CFD) solver within the open-source hydrodynamics framework REEF3D. This method satisfied the computational efficiency and high fidelity of the simulation of extreme wave events by using FNPF to provide far-field wave generation and propagation information and adopting CFD to calculate the near fluid field physical characteristics and impact details required when modelling the process of extreme states. The dynamic responses, including surge and heave motion of a semi-submersible under extreme waves, are carried out under typical extreme wave conditions. The numerical model is validated against experiments of rogue wave interaction with a semi-submersible platform. The HDC method achieved computational efficiency under the same wave conditions.
