Effects of Anisotropy on Natural Convection in a Vertical Porous Cavity Filled with a Heat Generation
Degan Gerard
Laboratory of Energetic and Applied Mechanics (LEMA), National University of Science, Technology, Engineering and Mathematics (UNSTIM), Abomey; BP 2282, Goho Abomey, Benin.
Sokpoli Amavi Ernest *
Laboratory of Energetic and Applied Mechanics (LEMA), EPAC - UAC, 01 BP 526, Cotonou, Benin.
Akowanou Djidjoho Christian
Laboratory of Energetic and Applied Mechanics (LEMA), National University of Science, Technology, Engineering and Mathematics (UNSTIM), Abomey; BP 2282, Goho Abomey, Benin.
Vodounnou Edmond Claude
Laboratory of Energetic and Applied Mechanics (LEMA), EPAC - UAC, 01 BP 526, Cotonou, Benin.
*Author to whom correspondence should be addressed.
Abstract
This research was devoted to the analytical study of heat transfer by natural convection in a vertical cavity, confining a porous medium, and containing a heat source. The porous medium is hydrodynamically anisotropic in permeability whose axes of permeability tensor are obliquely oriented relative to the gravitational vector and saturated with a Newtonian fluid. The side walls are cooled to the temperature and the horizontal walls are kept adiabatic. An analytical solution to this problem is found for low Rayleigh numbers by writing the solutions of mathematical model in polynomial form of degree n of the Rayleigh number. Poisson equations obtained are solved by the modified Galerkin method. The results are presented in term of streamlines and isotherms. The distribution of the streamlines and the temperature fields are greatly influenced by the permeability anisotropy parameters and the thermal conductivity. The heat transfer decreases considerably when the Rayleigh number increases.
Keywords: Natural convection, anisotropic porous medium, vertical rectangular cavity, Nusselt number, heat generation.