Convection pattern formation in a domain with a horizontal interface

Abstract

For the classical constellation of a fluid heated from below and cooled at the top, convection patterns are examined, with the additional feature of a horizontal interface. The interface separates two subdomains of different types, which contain porous media with different properties. The case of a pure diffusive layer at the bottom and the case of a free fluid above a porous medium are considered also. It is outlined that the approach can also be valid for the case of haline convection. Using finite element modeling for the nondimensional formulation, 2-dimensional transient and steady state convection patterns are visualized and examined. The simulations show that the interface significantly changes the convection cells in the domain as well as the heat transfer through the system. In all cases, the emerging pattern on one side of the interface is related to the pattern on the other side. The results are relevant for the understanding of heat and mass flow through layered geological strata, at the bottom of water bodies and in technical devices, for example layered insulation systems.