Effects of incident wind/wave directions on dynamic response of a SPAR-type floating offshore wind turbine system

As a promising renewable energy, offshore wind energy currently is gaining more attention, by which the economic and efficient operation of floating wind turbine systems is a potential research direction. This study is primarily devoted to the analysis of dynamic response of the NREL-5 MW reference wind turbine supported by an OC3-Hywind SPAR-type platform using a recompiled code which combines FAST with WAMIT. To verify the reliability of the recompiled code, the free decay motions of a floating wind turbine system in still water are examined with satisfactory results. After that, thirteen scenarios with different angles between wind and wave from 0° to 90° are investigated. The dynamic responses of the turbine system in various degrees of freedom (DOFs) for different incident wind/wave directions are presented in both time and frequency domains via the fast Fourier transform.