Dynamic Response of Moored 15MW Floating Offshore Wind Turbine in Tsunami-Waves

This study investigates the global performance of a moored floating offshore wind turbine (FOWT) and the dynamic response of mooring systems induced by Tohoku tsunami waves. To analyze the dynamic responses of moored FOWT platform, a 15MW semi-submersible type FOWT with a taut mooring system in shallow water is employed. The tsunami waves are modeled using a combination of three-component solitary waves. In the body nonlinear approach, the Froude-Krylov force and hydrostatic restoring force are obtained from the instantaneous wetted body surface at each time step. The results from the body nonlinear analysis are compared with those from the linear calculation for body displacement and mooring tensions. While the heave displacement is nearly identical, the surge and pitch displacements are smaller in the body nonlinear analysis than in the linear analysis. Although there is a slight difference in mooring tension, similar results are observed at the maximum peak point between the linear and body nonlinear calculations. Additionally, body responses are compared for various tsunami heights in the body nonlinear analysis.