Wind tunnel test of ice accretion on blade airfoil for wind turbine under offshore atmospheric condition

Abstract

For wind turbines under offshore conditions, ice accretion occurs on the blade surface in winter because of the cold and humid environment, which leads to the performance degradation of the wind turbine. The characteristics of icing on the wind turbine blade surface under the in-cloud condition with salinity are explored. A blade segment with an airfoil of NACA0018 is selected. The tests of icing on the blade surface in different conditions of salinities, temperatures, and wind speeds are conducted in a return-flow icing wind tunnel. Two parameters are defined to evaluate icing characteristics. The distribution and amount of ice are analyzed quantitatively. Results show that salinity can restrain the amount of ice accretion. Oppositely, low temperatures and high wind speeds can increase the amount of ice. A self-developed device was manufactured to measure the adhesion strength of ice. The effects of salinity, temperature, and wind speed on adhesion strength are studied. Research indicates that adhesion strength decreases sharply first and then slowly with an increase in salinity. Even though low temperature and high wind speed both increase the adhesion strength, the growth rate decreases. The research provides a reference for anti- and de-icing technologies of offshore wind turbines.