A Review of Coupling Approaches for the Dynamic Analysis of Bottom-Supported Offshore Wind Turbines

摘要

Offshore wind turbines are designed and analyzed using simulation tools (computer codes) capable ofrnpredicting the coupled dynamic loads and responses of integrated turbine and support structure systems.rnA partially coupled analysis using load exchange is often desirable to meet intellectual property rightsrninterests of disparate design teams and developers of the various components. Of interest is the assessmentrnof the validity of such partially coupled analysis approaches for offshore wind turbine systems withrnvarious types of foundations. Computer-aided engineering (CAE) tools—such as the National RenewablernEnergy Laboratory’s (NREL’s) open-source FAST software and commercial structural analysis andrndesign software—can use partial or full coupling to simulate loads and motions for utility-scale offshorernwind turbines with various support structures. In partially coupled analysis, computed tower-base loadsrnfrom the aeroelastic simulation tool are fed to structural response simulation tool at a suitable interface;rnrequired hydrodynamic and wind loads are introduced as needed on the exposed substructure. In fullyrncoupled analysis, the transfer is two-way—i.e., forces at the interface are intrinsically exchanged betweenrnthe aeroelastic and structural tools at each time step. It is desirable to compare the loads betweenrnalternative partially coupled models that are calibrated against a reference fully coupled case. This paperrnproposes a framework for the assessment of the validity of partially coupled models in the prediction ofrnshort-term and long-term loads and motions associated with large utility-scale bottom-supported offshorernwind turbines that might be deployed in offshore wind power development.