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

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.