A numerical study has been made of natural convection in an enclosure heated from below with a conductive partition. The upper and lower regions are filled with pure fluid and a fluid-saturated porous medium, respectively. Two-dimensional Navier-Stokes-equation and non-Darcian models (including inertia, boundary, and convective effects) govern the fluid region and the porous region. The major parameters of the problem are fluid Rayleigh number Ra, partition location height ratio (denotedHR), aspect ratio A, porosity ε, conductivity ratio of the partition to the fluid (denoted KR), and conductivity ratio of the fluid/porous matrix to the fluid ke/kf. The results indicate that the partition location and thermal conductivity significantly influence the heat transfer rate. Lower HR (a thinner porous region) and higher thermal conductivity ratio KR possess a higher heat transfer rate and intensify the occurrence of the onset of convection. In addition, high porosity and high effective thermal conductivity in the porous medium can increase the heat transfer rate. The increase ofNu is about 35 - 41%, with increase of ke/kf from 1-5 for porosity ranging from 0.4-0.6.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Aerospace Engineering
- Mechanical Engineering
- Fluid Flow and Transfer Processes
- Space and Planetary Science