Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

A wind tunnel investigation of a 2-D airfoil covered with various aircraft ground de-icing/anti-icing fluids at subfreezing temperatures has been conducted in the laboratory of the 'Groupe de Recherche de l'Ingenierie de l'Environnement Atmospherique' at Universite du Québec a Chicoutimi. The main objective of this investigation was to simulate take-off conditions in order to evaluate the behavior of these fluids on the airfoil surface, and to determine their effects on the aerodynamics of the model. The fluids tested include six products, some of which are similar to the fluids previously tested in flight (Boing 737) and with 2-D and 3-D models in the NASA Lewis Research Center. Calibration and development tests were then performed with the cruise airfoil model available in the laboratory (NACA 662-415 with a 30 cm chord and a 60 cm span). The profile was modified, by flap and slat additions, in order to obtain an aerodynamic performance approaching that of a large aircraft wing during take-off and to reproduce the flow-off of the fluid observed in flight tests. The experimentations confirmed the existence of a significant lift loss at all rotation angles. This phenomenon was found to be similar to that of a roughness element, placed at the leading edge of the wing model, and to be dependent on the presence of a fluid wave moving after rotation from underneath the wing leading edge. De-icing fluids exhibit lower lift loss than anti-icing fluids. Comparison with previous laboratory and flight tests showed general agreement in terms of fluid behavior with respect to lift loss. In particular, the study shows that, in the present generation of de/anti-icing fluids, the aerodynamic behavior deteriorates as the basic ice holdover endurance improves.