Numerical Simulation Of Ice Accretion On Aircraft Wings

When aircraft is flying in clouds with super-cooled droplets, the super-cooled droplets may freeze on aircraft surface. Lift decreases, drag increaes and stall angle of attack decreases when aircraft icing happens. Aircraft icing has seriouly affected flight safety.Methods of research on aircraft icing can be classified into three categories: engineering estimating, experiment and numerical simulation. A method of numerical simulation of icing accretion on aircraft is developed in this thesis.In terms of two-dimensional icing, A software for airfoil icing numerical simulation is developed and the icing influencing factors are analyzed thoroughly. According to icing conditions, the flow field can be calculated by Euler or N-S solver. Droplet impingment characteristics of airfoil are calculated based on Lagrange method. A Messinger-based icing model is established. Two dynamic grid methods for icing are developed. Comparison with the experimental ice shape date of a NACA0012 airfoil shows that the software is reliable. In the case of rime ice, a lot of numerical simulations are conducted for different conditions. Analysis conclusion is given by comparing the ice shapes under different conditions and icing mechanism analysis.In terms of three-dimensional icing, a method to turn three-demensional problem into two-dimensional problem based on the significance of stagnation location is developed. First the typical proiles on the wing are intercepted and the local angle of attack of each profile is obtained by considering three-dimensional effect. Then the ice shape of each profile is calculated by local angle of attack. Finally the ice shape on the wing is fitted by shapes of all the profiles, and effects of wing icing on the aerodynamic characteristics of the aircraft are researched.Finally, the work in this thesis is summarized and the future work is presented.