Modes of response of an offshore wind turbine with directional wind and waves

Maxime Philippe (1) , Aurélien Babarit (1) , Pierre Ferrant (1)

1 LHEEA - Laboratoire de recherche en Hydrodynamique, Énergétique et Environnement Atmosphérique

A coupled dynamic analysis of a floating wind turbine system has been performed to investigate effect of wave direction relative to wind on the system. Hydrodynamic loads are calculated by linear frequency domain approach and aerodynamic effect is taken into account by increasing hydrodynamic damping and restoring matrices with aerodynamic damping and gyroscopic stiffness. A modal analysis of the system was made to explain the calculated motions. It brings out the natural frequencies, natural modes and modal damping coefficients of the system. Excitation of natural modes, by waves explains the motion observed in the response amplitude operators, and the effect of wave direction relative to wind. This modal analysis helps to better understand the behaviour of floating wind turbine systems.

Mots clés: Modal analysis; Linear frequency domain response; Floating offshore wind turbine

Domaines: Mécanique des fluides [physics.class-ph]

Maxime Philippe, Aurélien Babarit, Pierre Ferrant. Modes of response of an offshore wind turbine with directional wind and waves. Renewable Energy, 2013, 49, pp.151-155. ⟨10.1016/j.renene.2012.01.042⟩. ⟨hal-01145150⟩