École Nationale Supérieure de
Techniques Avancées

Abstract

Offshore wind turbines are subject to a wide range of different waves and current conditions during their lifetime. Computing the hydrodynamic efforts on these structures is challenging. Precise models such as computational fluid mechanics (CFD) exist. However, the coupling with aerodynamics, mechanical structure and control is in this case not compatible with engineering studies. The strip theory is generally used to compute the main hydrodynamics loads from the velocity and the acceleration. These kinematics can be computed with the potential theory at different orders. In this work, we used second-order theory because it is the highest order of Stokes compatible with our spectral method. The spectral method consists of computing all kinematics at each time step on a fixed grid before interpolating the values on nodes of the structure. We first developed an independent tool to compute kinematics on a grid for an irregular second-order short crested wave field. Then we adapted DIEGO, the hydro-aero-servo-elastic tool of EDF to read this wave field. Finally we discuss second-order waves accuracy and choice for cost-efficient code.