High-Speed Imaging to Quantify the Transient Ice Accretion Process on a NACA 0012 Airfoil

Ice accretion on aircraft wings poses a performance and safety threat as aircraft en-counter supercooled droplets suspended in the cloud layer. The details of the ice accretion depend on the atmospheric conditions and the flight parameters. The icing process on the wing consists of a complex interaction of water deposition, surface water transport, and freezing. The aerodynamics affect the water deposition, the heat and mass transport, and ice accumulation; meanwhile, the accumulating ice affects the aerodynamics. Until now, most experimental measurements of aircraft icing have focused on the final ice shapes formed after exposure for a set duration to icing conditions. This approach fails to capture the transient processes that form the final ice formations. Here, we present experiments conducted in the Iowa State icing wind tunnel on a NACA 0012 airfoil to study the tran-sient ice accretion process under varying icing conditions. High-speed video of the icing process was acquired under controlled environmental conditions to quantitatively measure the transient water film run back, rivulet formation, and accumulated ice growth, and the experiments show how varying the environmental conditions modifies the ice accretion process. I