Development and Validation of a Frequency Domain Based Methodology for the Preliminary Design of Floating Offshore Wind Semi-Submersible Platforms

Abstract

Through this Thesis, a novel methodology for the preliminary design of floating offshore wind substructures has been developed. The main advantage is the significantly higher efficient, in terms of computational cost, compared the state-of-the-art tools. The primary contribution of this study resides in two novel methods that predict with reasonable accuracy the hydrodynamic loads up to 2500 times faster than the common radiation-diffraction analysis. The first method estimates the linear hydrodynamic coefficients, and the second method, the second-order hydrodynamic loads, which are usually neglected in the preliminary design phases due to the long simulation time required for their calculation. Both methods are integrated into a frequency domain response model to compose the novel tool presented in this Thesis. The results have been validated against the time domain based state-of-the-art tools. It is demonstrated that the proposed tool enables to narrow down the number of platform designs, achieving the similar conclusions as the conventional tools. Moreover, it enables to quickly perform sensitivity analyses that will provide knowledge to empower designers to make informed decisions and fine-tune the designs accordingly, ensuring optimal performance and stability.