Offshore wind turbines: a wind-fully nonlinear waves integrated model

This paper presents a numerical model capable of simulating offshore wind turbines ex- posed to extreme loading conditions. An external condition-based extreme response is reproduced by coupling a fully nonlinear wave kinematic solver with an aeroelastic simulator. The transient nonlinear free surface problem of water waves is formulated assuming the potential theory and a higher-order boundary element method (BEM) is used to discretize Laplace’s equation. For temporal evolution a second-order Taylor series expansion is implemente d. The code is successfully adopted to simulate overturning plunging breakers which give rise to danger ous impact loads when they break against wind turbine substructures. Emphasis is also placed on embedding the proposed numerical simulator into a general stochastic design framework. Finally, effects on the structural response obtained with the pro- posed model are discussed.