Double Diffusion in a Liquid Layer Underlying a Permeable Solid Region

Abstract

In this paper the main results are reported of a numerical investigation of transient double-diffusive convection in a fluid layer underlying a permeable solid region. Initially, the system is isothermal and possesses a linear distribution of salt in the permeable (porous) region. The system is cooled through its top boundary. The evolution of the transient flow, temperature, and species concentration fields is obtained numerically. In the course of this study the dependence of these fields is determined on the main problem parameters, exemplified by the thermal Rayleigh number, the species Rayleigh number, the Darcy number, the ratio of the height of the porous region to the height of the liquid layer, and the ratio of liquid to solid thermal conductivity. In addition, the above mentioned parameters are investigated in terms of their effect on the heat transfer rate at the top (cold) wall of the system as veil as on the heat and mass transfer rates at the porous-liquid interface.