Ice-accretion scaling using water-film thickness parameters

Studies were performed at INTA in Spain to determine water film thickness on a stagnation point probe inserted in a simulated cloud. The measurements were correlated with non-dimensional parameters describing the flow and the cloud conditions. Icing scaling tests in the NASA Glenn Icing Research Tunnel were then conducted using the Ruff scaling method with the scale velocity found by matching scale and reference values of either the INTA non-dimensional water film thickness or a Weber number based on that film thickness. For comparison, tests were also performed using the constant drop size Weber number and the average velocity methods. The reference and scale models were both aluminum, 61 cm span, NACA 0012 airfoil sections at 0 deg AOA. The reference had a 53 cm chord and the scale, 27 cm (12 size). Both models were mounted vertically in the center of the IRT test section. Tests covered a freezing fraction range of 0.28 to 1.0.