Hydrodynamic Responses of a Moored Semisubmersible Floating Offshore Wind Turbine in Steep Waves

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 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 (FOWTs) 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 article, the hydrodynamic performance of a semisubmersible platform of FOWT is modeled 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 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 modeling the process of extreme states. The dynamic responses, including surge and heave motion of a semisubmersible under extreme waves, are carried out under typical extreme wave conditions. The numerical model is validated against experiments of rogue wave interaction with a semisubmersible platform. The HDC method achieved computational efficiency under the same wave conditions.