We examine the linear stability problem for slot convection in which several passive diffusing species are allowed for. Such systems show multiply diffusive behavior, in which convective instability leads to the formation of horizontal layers. Our analysis resolves discrepancies found in the literature of the physical interpretation of the initial instability. Our results are directly compared to existing experimental results, showing good agreement with the observed initial layer formation, including measured quantities such as layer thickness. Our results also show the importance of closely monitoring (and controlling) the horizontal temperature gradient, since the results are highly sensitive to this physical ingredient.

• Received 20 January 1997

DOI:https://doi.org/10.1103/PhysRevE.57.1183