Influence analysis of rime icing on aerodynamic performance and output power of offshore floating wind turbine

Wind turbine blades are prone to icing under cold conditions, and the associated changes of blade airfoil geometry have a substantial impact on the aerodynamic characteristics and output power of an offshore floating wind turbine. Taking a 5 MW offshore floating wind turbine as the research object, and with consideration of marine meteorological conditions in a cold region, this study used fluid mechanics to predict icing on wind turbine blades. The influence on the aerodynamic performance of the blade airfoil by rime icing-related changes in its geometric shape was investigated, and the associated change in power production of a floating wind turbine was analyzed using blade element momentum theory. When the wind turbine blade condensed rime ice, the results showed that iced airfoil geometry was reasonably regular over a short period, and that icing was concentrated primarily in the tip area of the NACA64_A17 airfoil. The change of wind speed has a certain influence on the rime icing, and the temperature variation has little effect. Airfoil geometry change after icing had little effect on the lift coefficient (maximum decrease: ∼34%) but had greater impact on the drag coefficient (increase: 36%–200%). The power production of a wind turbine with an iced airfoil was approximately 17% lower than that of a wind turbine with a clean airfoil.