DOUBLE-DIFFUSIVE NATURAL-CONVECTION IN AN ENCLOSURE FILLED WITH FLUID-SATURATED POROUS-MEDIUM - A GENERALIZED NON-DARCY APPROACH

The double-diffusive natural convective flow within a rectangular encl osure has been studied using a generalized porous medium approach. The results have been validated with the help of theoretical heat transfe r results available for various porous medium flow models and also wit h the experimental results for double-diffusive convection in a fluid- filled rectangular cavity. The present generalized model covers the en tire range from Darcy flow to free fluid flow. Numerical predictions b y the model indicate that the flow pattern as well as the heat and mas s transfer are profoundly influenced by the buoyancy ratio. Also non-D arcy effects on flow, heat, and mass transfer become significant when the Rayleigh or Darcy numbers are large. The Sherwood and Nusselt numb ers become sensitive to bed porosity variation in the non-Darcy regime .