Numerical investigation and experimental validation of INO WINDMOOR semi-submersible FOWT in extreme waves

Abstract

Floating offshore wind turbines (FOWTs) are complex systems, as several physical phenomena are involved, and a complete numerical framework is essential for modeling such floating structures. In this study, the open-source hydrodynamics framework REEF3D is used to simulate the six-degrees-of-freedom (6DOF) motions of a moored floating body and a floating offshore wind turbine within a three-dimensional numerical wave tank (NWT). The numerical framework incorporates a quasi-static algorithm for mooring dynamics. A dynamic mooring model, MoorDyn, is also coupled with the FSI algorithm to assess the accuracy and reliability of the mooring algorithm. The mooring line tensions obtained by these models are compared against each other, and the motion responses of floating bodies are validated with the experimental results to demonstrate the accuracy of the numerical model. This study is also subjected to simulate dynamic responses of a floating wind turbine in highly nonlinear waves as well as very steep focused waves. To increase computational efficiency, Hydrodynamic-Coupling (HDC) between the fully nonlinear potential flow (FNPF) solver and the CFD solver in the open-source hydrodynamics framework is used to simulate the FOWT in focused waves. The numerical findings show that the HDC method increases computational efficiency without compromising accuracy.