In an effort to harness the abundant offshore wind resource over deepwater, the development of numerical design tools for floating offshore wind turbines (FOWTs) has progressed steadily in recent years. However, at present, a validated model capable of completely coupling the full elastodynamic response between the mooring system, floating support structure, turbine tower and the wind turbine is not commercially available.
The University of Maine has developed a new FOWT design, VolturnUS, which utilizes a concrete semi-submersible hull. For the VolturnUS design effort a number of numerical models were developed to analyze the system’s global performance. This paper presents the results of a validation study conducted to quantify the accuracy and suitability of a subset of these models for use in the design of the VolturnUS FOWT. Validation was conducted via comparisons of numerical model results to test data obtained from a 1:50 scale model testing campaign conducted by the University of Maine at the Maritime Research Institute, Netherlands offshore basin.
The validation study evaluated the performance and capabilities of the numerical models over a range of design conditions. Emphasis was placed on design load cases (DLCs), which were found to govern the design of the FOWT. The DLCs follow the American Bureau of Shipping’s (ABS) Guide for Building and Classing Floating Offshore Wind Turbines.
Through this method of model validation this work sought to quantify the numerical models’ accuracy, highlight their limitations, justify design assumptions, and identify areas requiring further development in the field of FOWT numerical modeling.Copyright © 2015 by ASME