Numerical analysis for the problem of steady natural convection heat transfer by double diffusion from a heated cylinder buried in a saturated porous media
CARLOS ALBERTO CHAVES1; JOSÉ RUI CAMARGO1; FRANCISCO JOSÉ GRANDINETTI1; WENDELL DE QUEIROZ LAMAS2; OSVAIR VIDAL TREVISAN3
1 UNIVERSIDADE DE TAUBATÉ; 2 UNIVERSIDADE DE SÃO PAULO; 3 UNIVERSIDADE ESTADUAL DE CAMPINAS
doi:10.20906/CPS/COB-2015-0110
Resumo
This paper aims to present numerical solutions for the problem of steady natural convection heat transfer by double diffusion from a heated cylinder buried in a saturated porous media, exposed to constant uniform temperature and concentration in the cylinder and in the media surface. A square finite domain 3 x 3 and acceptance criterion converged solution with an absolute error under 1 x 10-3 were considered to obtain results presented. The power law suggested for approaching of variables calculated T, C and  also was adopted. In order of method validation, an investigation of mesh points number in function of Ra, Le and N was done. A finite volume scheme has been used to predict the flow, temperature, and concentration distributions at any space from a heat cylinder buried into a fluid saturated porous medium for a bi-polar coordinates system. Examples presented show that the differences in the flow distribution caused by Rayleigh number range considered but also when Lewis number range is considered. Further, increase in the Rayleigh number has a significant influence in the flow distribution when the concentration distribution is considered. Steady natural convection heat transfer by double diffusion from a heated cylinder buried in a saturated porous medium is studied numerically using the finite volume method. To model fluid flow inside the porous medium, the Darcy equation is used. Numerical results are obtained in the form of streamlines, isotherms and isoconcentrations. The Rayleigh number values range from 0 to 1,000, the Lewis number values range from 0 to 100 and the buoyancy ratio number equal zero. Calculated values of average heat transfer rates agree reasonably well with values reported in the literature.
Palavras-chave: heated cylinder buried; Numerical analysis; saturated porous media; steady natural convection heat transfer; finite volume scheme