Investigation of viscous damping effect on the coupled dynamic response of a hybrid floating platform concept for offshore wind turbines

This study introduces a numerical scheme for investigating the effects of viscous damping on the dynamic response of a hybrid floating platform concept. The Floating Offshore Wind Turbine (FOWT) assemblage adopted for this study is the National Renewable Energy Laboratory (NREL) 5-MW baseline wind turbine mounted on a newly developed inhouse hybrid floating platform identified as the TRIgon Hybrid Floater (TRIHF). The TRIHF concept for FOWTs is developed based on the design principles that cuts across a Spar-buoy, Tension Leg Platform (TLP), and Semi-Submersible. The scheme employed for this study enhances the capability of a potential-based hydrodynamic solver by implementing the viscous damping coefficients obtained from a free decay numerical test. Results from this study confirms that the hydrodynamic response of the floating platform to rotational motion is highly impacted by the effect of viscous damping. However, the effect of viscous damping on translational motion is insignificant. © 2021 Elsevier Ltd