Sensitivity of Floating Wind Turbine Motions to Stable Boundary Layer Wind Profiles

Abstract Atmospheric stability influences the structural response of wind turbines by affecting both the wind profile and turbulence characteristics. Commonly used surface layer profile models, such as the logarithmic profile, are limited in their ability to account for the full impact of thermal stratification. Especially in stable conditions, with a shallow surface layer, the logarithmic profile overestimates the mean wind speed at higher altitudes relevant to modern wind energy applications. Moreover, stable atmospheres are commonly associated with features like low-level jets and significant wind veering, both of which can strongly affect the structural response of wind turbines, particularly for large rotor systems. This study investigates the sensitivity of a 15-MW floating wind turbine’s global motions to stable wind profiles derived from different models. Conventional logarithmic surface layer profiles are compared to Gryning boundary layer profiles and an analytical model for stable atmospheres that accounts for wind veering and the presence of low-level jets. Turbulent wind fields generated from these profiles are used as inputs for dynamic response simulations, focusing on the semi-submersible platform’s rigid body motions. The findings highlight the influence of stability-dependent shear on the platform motions, emphasizing the importance of using advanced profile models to reduce uncertainties in response simulations for the efficient design of wind turbine components.