Abstract:

Natural convective heat and mass transfer in a partially filled with porous medium was studied by using the two-domain approach. The Forheimer-Brinkman-Darcy equation was developed for the porous medium, whereas the Navier-Stokes equation was set up for the clear fluid region. A continuous interfacial condition was used at the interface between the clear fluid region and porous medium and the equations were solved by the finite element method with  weak constraint condition at the interface. Influences of thickness, permeability and porosity of the porous medium on heat and mass transfer were mainly considered. The numerical results showed that heat and mass transfer could be quickly weakened  when thickness of the porous medium is no more than 0.2. The flow became obviously slower when permeability decreased from 10^-3   to 10^-6 and also heat and mass transfer. Average heat and mass transfer velocities increased linearly with an increasing porosity.

Key words:  porous medium, natural convection, composite cavity, heat and mass transfer