The flexible multibody dynamics of a floating offshore wind turbine in marine operations

摘要

In this paper, a dynamic response analysis of a floating offshore wind turbine is performed during the rotor rotation under wind and wave loads after the turbine was installed on a floating platform. The floating offshore wind turbine is modelled as a system that consists of the floating platform, a tower, a nacelle, a hub, and three blades. Flexible multibody dynamics is employed in constructing the equations dealing with motion for the floating offshore wind turbine in the dynamic response analysis. The tower and the blades are constructed as flexible bodies by using the three-dimensional beam element. The external forces acting on the floating platform included the hydrostatic force, the hydrodynamic force, and the mooring force. Then, aerodynamic force was calculated based on the blade element momentum theory, and was applied to the blades. Using the wave and wind conditions that are generally required to operate a 5-MW offshore wind turbine, a numerical simulation was performed to determine the dynamic response of the floating offshore wind turbine, and the results are compared with the calculated dynamic response and stress based on a wind turbine analysis code that is open to the public. dynamic response analysis; floating offshore wind turbine; flexible multibody dynamics; static