A numerical investigation on the Marangoni stability under a convex meniscus in a vertical micro channel

Evaporating menisci have gained increasing attentions because of their wide applications. Recently, Gazzola, et al. have observed asymmetrical Marangoni flow patterns under a convex meniscus though the boundary conditions were symmetrical. The experimental results are distinct from those in previous literatures. In this paper, a numerical model is proposed to clarify the mechanism behind the abnormality. Factors including liquid evaporation at the interface, vapor transport in the gas domain, Marangoni effect and the natural convections are considered. The simulation well reproduced the experiments and further indicated that the symmetrical Marangoni convections under certain conditions are instable. Once a perturbation is performed, the original symmetrical convection will evolve to be a single vortex convection.EI091557-15603