ON THE STRUCTURE AND DYNAMICS OF DOUBLE DIFFUSIVE LAYERS IN SIDE WALL HEATING EXPERIMENTS.

The dynamics and structure of double-diffusive layers in side wall heating experiments with a stable density gradient were studied by means of different visualization techniques (shadow graph, fluorescent dyes and particles). The density gradient was produced using sodium chloride, sucrose, glycerine, hydrochloric acid, and polyvinyl alcohol. It is shown that the initial thickness of the layers depends on the undisturbed density gradient and fluid properties only, when the heating of the wall is not very fast. No layer formation was observed for very slow heating of the side wall even at supercritical Rayleigh numbers.