Abstract
We study Marangoni dropwise condensation of a binary vapor mixture in the framework of a long-wave model. The average mass and heat fluxes increase with respect to those in the flat-film state. We reveal that the increase of the average mass flux mainly arises from nonlinear coupling of the disturbances of the film thickness and the mass flux. Furthermore, we propose a simple expression for the average mass flux. This model suggests that the rate of the average mass flux to that in the flat-film state becomes larger at smaller ambient vapor concentrations of the lower-boiling-point component, which is consistent with experimental results.
