An Investigation On The Aerodynamic Of Airfoils With Control-surface And High-lift Airfoils Under Supercooled Large Droplets Icing Condition

Supercooled Large Droplet(SLD)Icing is more complex than normal droplet.The aerodynamic character of an iced airfoil is closely related to the geometry feature of the ice,yet it's still unclear the effect of SLD icing on the flow field and aerodynamic coefficient of airfoil with control surface and airfoil of Multi-wing.For the airfoil with control surface,the flow field around the airfoil with horn-ice and ridged-ice is simulated with unsteady numerical method,the quantitive relations of Lift coefficient with angle of attack and deflection of control surface is obtained,and the difference of the aerodyanmic derivative in different conditions is analyzed.A three-step plunge of the aerodynamic derivative of horn-ice airfoil is found to be a consequence of variation in AOA and the deflection;while a two-step plunge with a greater down slope is found to be associated with the derivative for a ridged-ice airfoil.The different geometry of icing with SLD and normal droplet in various icing time is simulated and their effect on aerodynamic characters is compared.For airfoil of multi-wing,the geometries of airfoil with SLD and normal droplet icing is generated by icing simulation program,and the consequent aerodynamic features are compared by analyzing the streamlines,vorticity field near the slat and flap,as well as the pressure coefficient on the airfoil.The result shows that: the depletion of the lift coefficient by icing of droplet with 20 um diameter is up to 17.5% and that with 400 um diameter reaches 72.5% in maximum,together with a drastically diminished stalled angle of attack.This research reveals the unusualness and severity of the SLD icing.