Aero Elastic Control Floater Mooring Coupled Dynamic Analysis of Floating Offshore Wind Turbine in Maximum Operation and Survival Conditions

Abstract

Increasing numbers of floating offshore wind turbines (FOWTs) are planned in the coming years due to their high potential in the massive generation of clean energy from ocean wind. In the present study, a numerical prediction tool has been developed for the fully coupled dynamic analysis of an FOWT system in the time domain including aeroloading, tower/blade elasticity, bladerotor dynamics and control, mooring dynamics, and platform motions so that the influence of aeroelasticcontrol dynamics on the hullmooring performance and vice versa can be assessed. The Hywind spar design with a 5 MW National Renewable Energy Laboratory (NREL) turbine is selected as an example and two different collinear windwavecurrent environmental conditions, maximum operational and survival conditions, are applied for this study. The maximum operational condition means the maximum environmental condition with normal bladeturbine operation and the survival condition represents the extreme situation without any bladeturbine operation. Through this study, it is seen that the ultimateloading environments for different structural components of the FOWT can be different. The developed technology and numerical tool are readily applicable to the design of any type of future FOWTs in any combinations of irregular waves, dynamic winds, and steady currents.