Separation of a binary liquid mixture in compound system: Fluid–porous–fluid

We report results on a computational study of double-diffusive convection with Soret effect in a system consisted of a fluid region adjacent to a porous medium, which is saturated with the same liquid. The liquid is a binary mixture with positive Soret coefficient. The flow in the system is driven by buoyancy force due to imposed temperature difference between lateral walls. The study is focused on components separation due to the Soret effect through the porous medium in presence of liquid regions near its side walls. The problem is solved in each domain independently. A non-stationary Darcy–Brinkman model is used to calculate momentum, heat and mass transport and continuity equations in the porous medium, while full Navier–Stokes equations are solved in the pure fluid. It is demonstrated that presence of free liquid volumes near the lateral walls strongly affect the process of separation in the porous medium.