To obtain the aerodynamic loads of a floating wind turbine with rotation and pitching motion, a numerical simulation method based on FAST is established. The OC3 Hywind-NREL 5MW is taken as the research object, the aerodynamic load coefficient and energy utilization coefficient at different wave period were analyzed. The results show that the time history curve of the aerodynamic coefficient and energy utilization coefficient have obvious periodic fluctuations. The fluctuation frequency of aerodynamic load coefficient and energy utilization coefficient curve depends on wave frequency; The average value of the fluctuation depends on the aerodynamic load coefficient and energy utilization coefficient of the wind turbine when it does not surge. The amplitude of the fluctuation increases with the increase of wave period. On this basis, the damping and added mass coefficients are obtained based on the least square method. The amplitude of aerodynamic coefficient and energy utilization coefficient of wind turbine have big correlation with damping coefficient. The research findings can provide relevant data for studying the coupled motion of floating wind turbine.
The problems caused by traditional fossil energy are increasingly serious, and people are now actively developing clean and renewable energy. Wind energy is a renewable and non-polluting energy source that has received increasing attention in recent years. The concept of floating wind turbines was first proposed in 1972 by Professor Heronemus (Heronemus, 1972) at the University of Massachusetts, Amherst, USA. In 2009, Hywind, the world's first floating wind turbine, was commissioned off the coast of Norway. The wind turbine is invested and built by Equinor, Norway. In 2011, Principle Power developed the WindFloat and installed a sea trial prototype which is a single Vestas V80-2.0MW wind turbine. In 2017, the first floating offshore wind project was commissioned. Because of the advantages of stable operation, high efficiency and large installed capacity, floating wind turbines have attracted widespread attention from experts and scholars in various countries. (Wan and Cheng, 2017)
