Experimental and Numerical Investigations of Deicing and Anti-Icing Fluid Performances under Various Precipitation Conditions

Recognition of the need for safe ground aircraft anti-icing products with extended holdover times, and awareness of the related take-off perturbations, have been steadily growing during the 1980's. Standard laboratory testing procedures have been established by regulators to assess both holdover and aerodynamic performances of the commercial anti-icing fluids to be used on airports. Unfortunately, the standard laboratory evaluation procedures do not cover all the conditions encountered in natural cold precipitations which, at times, can vary with respect to the limited conditions simulated in laboratory. Therefore, a research work, on this subject, has been undertaken at the Université du Québec à Chicoutimi (UQAC) with the main objective of identifying the response of deicing and anti-icing fluids under a wide range of icing conditions.

Since laboratory constraints are limiting the capability of reproducing all types of natural icing events, various numerical simulations were developped to study the freezing process of a de/antiicing fluid. These simulations address two situations of the fluid behavior: the state of almost rest on an inclined plate, and the state of high shearing during take-off. To complement this effort, laboratory experimentations were also performed, where icing parameters were varied to increase available data, especially in terms of precipitation rate. This paper intends to present the results derived from the numerical simulations developped under this research program in relation to the experimental data obtained in icing simulations.