Dynamic Analysis of a Barge-Type Floating Wind Turbine Subjected to Failure of the Mooring System

Abstract

Evidence points to increasing the development of floating wind turbines to unlock the full potential of worldwide wind-energy generation. Barge-type floating wind turbines are of interest because of their shallow draft, structural simplicity, and moonpool-damping effect. Based on the BEM potential flow method, this study uses ANSYS-AQWA software to create a floating-barge moonpool platform model equipped with an OC5 NREL 5 MW wind turbine, to study the effect of the damping lid method on the resonance of the moonpool gap water, the wind–wave coupling effect, and the dynamic response of the FOWT and mooring system after single-line and double-line failure. The results show that the damping lid method, based on the potential flow theory, can effectively correct the effect caused by the lack of viscosity; the effect of a single breakage of upwind mooring lines on the motion is mainly in the sway and yaw modes, and after mooring line 8 breaks, the maximum tension of the adjacent mooring line increases by 2.91 times compared to the intact condition, which is 58.9% of the minimum breaking strength; and the breakage of two mooring lines located at one corner leads to a surge drift of up to 436.7 m and a cascading failure phenomenon.