The icing process of an aircraft: drop dynamics and wetted surface

Dynamics of water droplets of various size in the vicinity of the leading edge of an airfoil is investigated. Bending of drop trajectories (and, consequently, the extention of a wetted wing surface) is shown to depend significantly on the drop deformation and Saffman force, arising in the boundary layer. (Influence of a “near-surface force” caused by the “drop imaginary reflection” is far less). A maximum in the dependence of wetted surface extention on the initial drop radius is revealed. Hence, air viscosity, drop deformation and its break-down in front of a flying apparatus are really important for the following icing process.