Investigation of a FAST-OrcaFlex Coupling Module for Integrating Turbine and Mooring Dynamics of Offshore Floating Wind Turbines: Preprint

To enable offshore floating wind turbine design, the following are required: accurate modeling of the wind turbine structural dynamics, aerodynamics, platform hydrodynamics, a mooring system, and control algorithms. Mooring and anchor design can appreciably affect the dynamic response of offshore wind platforms that are subject to environmental loads. From an engineering perspective, systembehavior and line loads must be studied well to ensure the overall design is fit for the intended purpose. FAST (Fatigue, Aerodynamics, Structures and Turbulence) is a comprehensive simulation tool used for modeling land-based and offshore wind turbines. In the case of a floating turbine, continuous cable theory is used to emulate mooring line dynamics. Higher modeling fidelity can be gainedthrough the use of finite element mooring theory. This can be achieved through the FASTlink coupling module, which couples FAST with OrcaFlex, a commercial simulation tool used for modeling mooring line dynamics. In this application, FAST is responsible for capturing the aerodynamic loads and flexure of the wind turbine and its tower, and OrcaFlex models the mooring line and hydrodynamic effectsbelow the water surface. This paper investigates the accuracy and stability of the FAST/OrcaFlex coupling operation.