The Influence Of Airfoils Ice Accretion On Flight Safety

When flying in icing weather conditions, the areas of aircrafts prone to ice accretion are: airfoil,tail, propeller blade, leading edge of engine inlet, windshield, pitot, antenna and so on. The maineffect of wing icing is to change the aircraft’s aerodynamic shape, and affect its aerodynamiccharacteristics, which is a serious threat to flight safety. So research of icing on airfoils has been aimportant part in aircraft design. So the wing icing research has always been the world’s attention. Tostudy the impacts of the shape changes on the aerodynamic characteristics of the wings, first of all thewater droplets impinged should be studied, as well as the mechanism and the process of freezing onthe wing surface, that is, the growth of the ice and the ice shape after a certain period of time.The main research of this paper includes:1. This paper reviews and summarizes the basicconcept of ice accretion, ice hazards, modern anti/deicing technology and the necessity for ice studies;2. This paper uses N-S equation to compute the air flow when icing, selects S-A aircraft icing researchmodel in turbulence models, establishes two-phase flow of air and super-cooled water dropletsequations, determines the droplet trajectories, gets water droplets impinge regions and the local waterdroplets collection coefficient on the icing surface, determines the characteristics of droplet, andconsiders the ice surface roughness in the model;3. This paper proposes a new method to calculatethe equivalent roughness height. This method embeds the influence of ice surface roughness bycombining with SA turbulence model. The results are compared with experimental data and theempirical formula method widely used in the world;4. This paper compares the calculated resultswith experimental results, and discusses the affect of the flight and weather condition parameters onthe ice shape; and discusses the influence of wing icing on the aerodynamic performance;5. Finally,this paper makes prospects on anti-deicing methods by numerical simulation.