An Integrated Nonlinear Wind-Waves Model for Offshore Wind Turbines

Marino, Enzo

Enzo Marino graduated cum laude (five-year degree) in Structural Engineering at the University of Florence. In 2010 he received his PhD from the joint international doctoral school of the University of Florence and TU-Braunschweig. Currently he is a post-doctoral researcher and teaching assistant for the courses of Solid Mechanics and Computational Mechanics at the University of Florence.

Serie: Premio Tesi di Dottorato

This thesis presents a numerical model capable of simulating offshore wind turbines exposed to extreme loading conditions. External condition-based extreme responses are reproduced by coupling a fully nonlinear wave kinematic solver with a hydro-aero-elastic simulator.
First, a two-dimensional fully nonlinear wave simulator is developed. The transient nonlinear free surface problem is formulated assuming the potential theory and a high-order boundary element method is implemented to discretize Laplace's equation. For temporal evolution a second-order Taylor series expansion is used. The code, after validation with experimental data, is successfully adopted to simulate overturning plunging breakers which give rise to dangerous impact loads when they break against wind turbine substructures.
Emphasis is then placed on the random nature of the waves. Indeed, through a domain decomposition technique a global simulation framework embedding the numerical wave simulator into a more general stochastic environment is developed.
The proposed model is meant as a contribution to meet the more and more pressing demand for research in the offshore wind energy sector as it permits taking into account dangerous effects on the structural response so as to increase the global structural safety level.