Self-Limited Ice Formation and Efficient De-Icing on Superhydrophobic Micro-Structured Airfoils through Direct Laser Interference Patterning

Forward facing aerodynamic surfaces such as rotors and wings are susceptible to ice build-up when exposed to atmospheric icing conditions. If not removed, accumulated ice on aircraft surfaces affects aerodynamics or rotation balance, which can ultimately lead to increased fuel consumption, reduced operational performance and to potentially hazardous situations. Laser surface structuring is proposed as an alternative technology to coatings for achieving icephobic properties and support anti-icing and de-icing processes on aerodynamic surfaces. However, to authors' knowledge, no study available in the literature reports on the icing behavior of microtextured curved aerodynamic profiles and the effect of the laser surface treatment on the electrothermal heating used for ice protection systems. In this work, direct laser interference patterning is employed to fabricate hierarchical micro- and nanostructures directly on a non-planar titanium airfoil. The anti-icing performance of the laser-treated airfoil is tested in an icing wind tunnel under simulated atmospheric conditions. The results demonstrate a self-limiting ice growth, a decrease in the deicing electro-thermal power up to 80%, and up 60% lower heating power necessary to keep the surface free of ice than on the reference airfoil.