Free Surface Natural Convection In A Differentially Heated Rectangular Cavity

An experimental and numerical study has been made of natural convection in an open cavity. It was found that the presence of a free surface increases the hotcold asymmetry of the bulk flow. At the free surface, a very slow recirculation was detected which appears to be decoupled from the main circulation in the cavity. Using standard free-surface boundary conditions, numerical modelling properly reproduced the bulk flow characteristics, but not the surface flow. A novel kinematic representation of the surface layer enabled the experimentally observed surface flow to be reproduced numerically. 1 Introduction Free surface flow is attracting increasing attention due to new material processing technologies such as laser welding, glass processing and the growth of high purity crystals. However, relatively little experimental or numerical work has been done for three-dimensional flows. Hence, our aim is to examine the effects of the free surface on natural convection for the popular bench-...