- Poulikakos, D. and Bejan, A., NATURAL CONVECTION IN VERTICALLY AND HORIZONTALLY LAYERED POROUS MEDIA HEATED FROM THE SIDE.,
International Journal of Heat and Mass Transfer, vol. 26 no. 12
pp. 1805 - 1814 .
(last updated on 2007/04/08)
The effect of nonuniform permeability and thermal diffusivity is investigated numerically. The first part of the study focuses on systems composed of vertical sublayers. It is shown that the heat transfer rate is influenced substantially by the thickness and permeability of the peripheral sublayers adjacent to the heated vertical walls. The heat transfer results are correlated by using the ratio of peripheral sublayer thickness divided by the boundary layer thickness based on peripheral sublayer properties. The second part of the study deals with porous systems composed of horizontal sublayers with different permeabilities. It is shown that due to the lack of homogeneity the vertical walls of the system are lined by boundary layers whoe thicknesses vary from one sublayer to the next. A general heat transfer scaling law for horizontally layered systems is reported.