Effects of ice accretions on aircraft aerodynamics

Aircraft icing: an ongoing threat to aviation safety

A model for the flow of a thin film, with and without solidification, on an arbitrary three-dimensional substrate is presented. The problem is reduced to two simultaneous partial differential equations for the film and solid layer thicknesses. The flow model (with the solidification rate set to zero) is the first such model to describe thin film flow on an arbitrary three-dimensional surface. Various limits are investigated to recover previous models for flow on flat, cylindrical and two-dimensional curved surfaces. With solidification a previous model for accretion on a flat substrate is retrieved. It is shown how the model may be reduced to standard forms, such as solidification on a flat surface, circular and non-circular cylinders, aerofoils and spheres. Numerical solutions are obtained by combining an ADI scheme with a shock capturing method. Results are presented for flow and accretion on a flat surface, aerofoil and sphere.

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The flow and solidification of a thin fluid film on an arbitrary three-dimensional surface

An experimental investigation on the unsteady heat transfer process over an ice accreting airfoil surface

Piezoelectric actuations for simultaneous generation of shear and impulse forces for effective and energy efficient de-icing applications are proposed. Aircraft leading edge structures are considered for analysis and lab experiments. Piezoelectric actuators are affixed on the inner surface of the leading edge at the locations where highest amount of ice accretion on the outer surface has occurred. Simultaneous shear and impulse force generation is achieved with actuators consisting of two sets of electrodes, one arranged in parallel to the poling direction, and the other perpendicular to it, to generate shear forces and normal forces, respectively. Finite element models of the leading edge structure with ice accretion layer are formulated. Simulations of the de-icing process are performed and the actuator locations, electric charge applied, and impulse duration are optimized to achieve effective ice removal

R.J. Kind

Papers

Experimental and computational simulation of in-flight icing phenomena