Heat and mass transfer through condensation, in an incompressible turbulent boundary layer, on a flat plate with low level exchange

Theoretical and experimental results from an examination of the thermal flux in the flow of a fluid (at a certain temperature) over a cooled wall (at a different temperature) are reported. Wind tunnel trials were performed with an air/water mixture flowing at 5.5 m/sec over a flat brass plate. The heat transfer between the flow and the plate was decomposed into the convective component expressed by the difference in temperature between the free flow and the surface, vapor condensation in the free flow defining the latent heat, and the mass flow from vapor into a condensed phase. Limiting conditions and the energy equations were formulated according to the theory of thin layers, taking into account the temperature gradient along the wall and the conservation of mass. The theory of thin layers was effective for calculating condensation, so long as the profiles remained asymptotic. A similarity was noted between condensation and thermal aspiration. The method is useful for modeling both laminar and turbulent boundary layers.