A large number of offshore wind farms with fixed foundation have been built in Europe with the relatively state-in-art techniques. Much of the offshore wind source potential in United States, China and other counties is available in the water depth more than 50 meters, where floating offshore wind turbine shows their economic potential. Comparing with the onshore system, the offshore wind turbines sustain more complicated environment conditions with stochastic wind and wave. The floating offshore wind turbine (OWT) is still in their early stage. As a whole system, OWT is designed and analyzed using simulation tools capable of predicting the coupled wind-inflow, aerodynamic (aero), control system (servo), and structural-dynamic (elastic), incident waves, sea current, hydrodynamics (hydro), and foundation dynamics of the support structure in a coupled simulation environment. The so called aero-hydro-servo-elastic modeling is needed. In this work, the three-blade 5MW upwind wind turbine, which is the basic model under IEA Annex 23 Subtask 2 Offshore Code Comparison Collaboration (OC3) project, is supported by an OC3- Hywind spar buoy platform. The platform is connected by three mooring lines to the seabed. Coupled aero-hydro-servo-elastic model with full flexible components including the platform, blades, tower and drivetrain is used in the simulation by the open source code. Several primary design load cases with different wave and wind condition are investigated. The natural frequency, damping ratio, the statistic and frequency domain responses of the system are included.
With the development of the industry, energy is becoming one of top 10 problems for the humanity in next 50 years. To release the dependence on coal, oil and other traditional energy resources with green house gas emission, people are paying more attention to new and renewable energy. Wind energy has developed very fast during last 30 years.
