Thermosolutal natural convection cooling process of a thermal source inside a partially porous cavity

Abstract

Abstract This work deals with the numerical study of the thermosolutal natural convection from a heat source immerged in a porous layer, which is placed vertically inside a square cavity. All walls of the cavity are thermally insulated, except the right wall, which is maintained at cold temperature. For the mass boundary conditions, the vertical walls are subjected to a gradient of concentration, whereas the horizontal walls and the part of the left wall that contacts with the heat source are impermeable. The finite volume method and the SIMPLER algorithm are employed to solve the mathematical equations. The effects of several geometrical and physical parameters are analyzed, such as vertical heat source positions (0 ≤ Yp ≤ 0.8), the porous layer thickness (0 ≤ Xp ≤ 1), the thermal conductivity ratio (1 ≤ Kr ≤ 100), Darcy number (10−6 ≤ Da ≤ 10−2), Rayleigh number (104 ≤ Ra ≤ 106), Lewis number (0.1 ≤ Le ≤ 10), and the buoyancy ratio (-5 ≤ N ≤ 5). The results indicate that the best cooling of the heat source is observed when the Yp is located between 0.38 and 0.55. Moreover, the case of coupling heat and mass transfer (N ≠ 0) offers low maximum heat source temperature compared to that of the classical natural convection (N = 0), especially with an increase in the Ra number and N and/or a decrease in the Le number. In addition, an increase in the thermal conductivity ratio and the permeability of the porous layer (Da) enhances the cooling process of the thermal source.