Effect of Superhydrophobic Coating on the Anti-Icing and Deicing of an Airfoil

Ice accumulation on aircraft wings can cause a loss in lift and increased drag. The present research investigates the effect of using a superhydrophobic coating, applied on an aluminum small-scale two-dimensional NACA 0012 airfoil, on ice accretion. The coating used is a commercial product that provides a contact angle of 160 deg, whereas the contact angle hysteresis is 6 deg. Experiments are conducted in a small-scale closed-loop icing wind tunnel at flow velocities ranging from 10 to 23 m/s, air temperatures from 0 to -15 degrees C, a liquid water content between 1.0 and 4.8 g/m(3), and a mean volume diameter from 25 to 60 mu m. The experiments show that, compared to the aluminum airfoil, the superhydrophobic airfoil counteracts the formation of ice at air temperatures as low as -10 degrees C. The results indicate a 50% power reduction to keep the superhydrophobic airfoil ice free in the simulated icing conditions and a time reduction of 75% to deice the airfoil when compared to the aluminum airfoil. It is deduced that no ice accretes on the airfoil when only its direct droplet impact area is covered with the superhydrophobic coating in anti-icing mode.