Effects of nonuniform heating and thermocapillarity in evaporating films falling down an inclined plate

摘要

The dynamics of a thin evaporating liquid film falling down an inclined plate is studied in the cases of both uniformly and nonuniformly heated plates. The film flow is influenced by gravity, mean Surface tension. thermocapillary force and mass loss. The dynamics of the two-dimensional evaporating film is Studied by the use of long-wavelength theory. numerical Solution of the evolution equation indicates that the evaporation has a strong stabilizing effect oil the film instability and that a sequence of instability. stability and then instability of the falling film its evaporation exists. The effect of nonuniform heating is dominant prior to film disappearance and it enforces film rupture. Due to the joint action of thermocapillarity and evaporating mass loss. the film evolution exhibits the formation of multi-hump structures. the downstream Propagation of which is suppressed. When the nonuniformities in the imposed temperature differences are increased. large deformations Of the liquid-vapor interface occur that lead to all enhancement of the heat transfer processes.