Aerodynamic damping in decoupled dynamic modeling of floating offshore wind turbines

Accurate and efficient modeling of floating offshore wind turbines (FOWTs) is crucial for fast iteration and optimization of design solutions. However, the commonly used coupled models are normally time-consuming, data intensive, and hard to satisfy the requirement of fast prediction of environmental loads. By contrast, efficient decoupling methods of FOWTs are still insufficiently accurate and require further investigation. As a result, this paper focuses on the effects of aerodynamic damping on the prediction accuracy in decoupled simulations. Firstly, an aerodynamic model is established for the referenced wind turbine, which is used to identify both the constant and frequency-dependent aerodynamic coefficients. Subsequently, decoupled models are developed for the referenced FOWT by treating the aerodynamic thrust forces as concentrated loads, incorporating aerodynamic damping and added mass as ‘additional’ components of the original hydrodynamic coefficients. By comparing the surge and pitch responses between the decoupled and coupled models, the role and applicability of aerodynamic damping in decoupled models are demonstrated. Our findings highlight the substantial influence of the frequency-dependent characteristics of aerodynamic damping on the decoupled analyses, offering valuable insights for the establishment of efficient and accurate decoupled models in practical engineering design. • We presented an efficient decoupled approach for dynamic analysis of FOWTs. • We illustrated the effects of constant and frequency-dependent aerodynamic damping on motion responses of FOWTs. • We emphasized the importance of frequency dependence of aerodynamic damping in decoupled analyses of FOWTs.