Dynamic Performance Optimization of a Floating Offshore Wind Turbine Based on Fractal-Inspired Design Principles

Floating offshore wind turbines (FOWTs) are increasingly gaining attention for their ability to operate in deeper waters. However, the dynamic responses of FOWTs are amplified significantly under the complex sea conditions, posing challenges to the overall system stability. This study proposes a novel semi-submersible platform featuring fractal structure inspired by Victoria Amazonica as solutions to the stability of FOWTs. The study uses computational fluid dynamics method to investigate the impact of fractal characteristics on hydrodynamic response of the novel platforms. Furthermore, the dynamic responses of FOWTs fitted with an 8-level fractal structure (8LFS-FOWT) are analyzed under fully coupled conditions. Following the increase in fractal dimension, the cavity size within the fractal structure gradually decreases, resulting in the decomposition of originally larger vortices into multiple smaller-scale vortices. These smaller vortices present higher velocity gradients and greater viscous dissipation, effectively absorbing wave energy and improving platform stability. The fully coupled analysis reveals the most pronounced improvement in power and pitch stability for 8LFS-FOWT, with standard deviations reduced by 12.75% and 25.10%. The vortex distribution within fractal structure presents a self-similarity consistent with fractal characteristics, enabling the cascade process of energy across different scale vortices, thereby enhancing wave energy absorption efficiency.