Review Article

Abstract

A review is provided of salient findings, old and recent, about Benard convection flows in a liquid layer heated from below and open to the ambient air. Instability and subsequent convective patterns past the instability threshold are the consequence of surface tension gradients acting along the open surface and by the temperature gradient maintained across the liquid layer. The onset of hexagons, rolls, squares and their relative stability is described here as well as the appearance of more complex patterns like labyrinthine convection flows. Asymptotic unsteadiness is also expected near the instability threshold as a consequence of the non-variational character of the problem, hence a precursor of space-time chaos, interfacial turbulence already possible at low Marangoni number.