Comparative Study of Using Superhydrophobic and Icephobic Surface Coatings for Aircraft Icing Mitigation

Abstract

We report a comparative study to evaluate the effects of surface coatings with different hydrophobicities and icephobicities on the performance of a hybrid anti-/de-icing system that integrates surface heating with hydro-/ice-phobic coating for aircraft icing mitigation. While a flexible electric film heater wrapped around the leading edge of an airfoil/wing model was used to heat the airfoil frontal surface to prevent ice accretion near the airfoil leading edge, three different kinds of coatings were applied to coat the airfoil model at three distinct spanwise locations, which included an icephobic coating with an outstanding icephobicity but a weak hydrophobicity; a superhydrophobic surface (SHS) coating with outstanding water repellency but a moderate icephobicity; and a commonly used hydrophilic coating with poor hydrophobicity and poor icephobicity. Surface wettability was found to play a more important role than icephobicity in affecting the performance of the hybrid anti-/de-icing systems. In comparison to the approach of forceful heating the hydrophilic airfoil surface, the hybrid approach with the SHS coating was found to be able to achieve about 90% energy savings in keeping the entire airfoil surface ice-free; the corresponding energy savings for the hybrid system with the icephobic coating was only about 10%.