Features of the liquid interaction with surfaces as applied to the problem of aircraft icing

Managing the interaction of liquids with surfaces is of great interest over a wide range of practical applications: the possibility of aircraft complete ice protection, a reduction of the friction coefficient by tens of percent, an increase in fluid flow in pipes and channels; however, the models of a number of the above processes are far from completion. This paper describes the flow modes of liquid around a hydrophobic body containing air in its pores in application to problems of aircraft icing and reducing liquid friction when it flows around solid bodies. Analytical expressions for liquid flow in channels, where lubrication on the walls allows for sliding, have been obtained, as well as estimates of parameters for washing away of the air lubrication layer from the pores of the hydrophobic coating. Using examples of flow between plates and in a cylindrical pipe, the influence of the lubrication layer thickness on fluid flow is shown, specifically demonstrating the potential increase in flow by several tens of percent due to sliding. A physical-mathematical model has been developed for calculating the elementary interaction act of a flow molecule with a solid body to reduce the time of molecular simulation while taking into account important physical features. New original analytical expressions for the rebound coefficients of molecules from the surface of a solid body have been obtained, depending on its physical properties and temperature. Interaction models have been developed using the example of water molecule and solid aluminum body, with values of the velocity change coefficients for molecular during collision obtained. Based on an analysis of known experimental data, the dependence of the contact angle of water droplets on a flat surface on the Debye temperature of the material has been demonstrated. The results obtained and the developed mathematical models can be used to create coatings that prevent or completely eliminate aircraft icing, particularly the formation of barrier ice during the flow of solidifying liquid film and droplets on the surfaces of streamlined elements of the aircraft.