Atmospheric Icing Effects on Aerodynamics of Wind Turbine Blade

Abstract

A significant degradation in the aerodynamic performance of wind turbine system can occur by ice accretion on the surface of blades operated in cold climate. The ice accretion can result in performance loss, overloading due to delayed stall, excessive vibration associated with mass imbalance, ice shedding, instrumental measurement errors, and, in worst case, complete wind turbine system shutdown. In this study, the similarity and difference between atmospheric icing (wind turbine) and inflight icing (aircraft) are first identified. In particular, nature of cloud, iced area, ice sensor location, and efficient anti/de-icing systems for wind turbine are discussed. Then the impact of ice accretions on the aerodynamic characteristics of wind turbine blade sections is investigated on the basis of modern CFD method. It is shown that the thickness of ice accretion increases from the root to the tip and the effects of icing conditions such as relative wind velocity play significant role in the shape of ice accretion. Finally, the computational results are used to predict three-dimensional aerodynamic characteristics of wind turbine blade through the blade element momentum method.