Investigation into a hybrid mooring system with hydrodynamic response and mooring tension from a DeepCwind floating wind turbine

This paper investigates the effect of buoys and a clump weight on the mooring lines and the dynamic response of the floating platform. The full-scale of the OC4-DeepCwind semisubmersible FOWT platform is analyzed using the boundary element method (BEM) with ANSYS-AQWA software, when considering regular wave conditions. Platform motions and mooring line tension in the surge, heave, and pitch are presented and discussed in the time domain analyses (TDA) and frequency domain analyses (FDA). Validation is performed by compression of the platform motion RAO and the fairlead tension RAO magnitudes in the surge, heave, and pitch (for both numerical and experimental data) under seven sea states’ regular waves. The results show that increasing the number of buoys at a constant volume decreases the surge and pitch motion amplitude, while the heave motion increases slightly. Adding the buoy and clump weight (type 1) to the mooring line reduces the oscillation amplitude tension. In addition, raising the number of buoys increases the oscillation tension.