Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

A NUMERICAL ANALYSIS FOR HIGH MODIFIED RAYLEIGH NUMBER NATURAL CONVECTION IN ENCLOSURES CONTAINING A POROUS MEDIUM

Get access (open in a dialog) DOI: 10.1615/IHTC8.3830
pages 2647-2652

Abstrakt

A nonuniform grid size numerical method was used to investigate steady-state natural convective heat transfer in rectangular enclosures filled with a porous material. The enclosures were considered to be two-dimensional and were assumed to have isothermal vertical and adiabatic horizontal walls. Of interest were the heat transfer characteristics in the high modified Rayleigh number regime (150 < Ra0 < 500).
The governing equations, based on the Brinkman-extended Darcy model, were discretized using central three-point differences. The boundary-layer thickness predicted by analytical analyses was used to identify the boundary-layer and the core regions. Inside the boundary layers a grid size smaller than that in the core was employed. By doing so, numerical instabilities due to sharp gradients were avoided while the overall number of grid points required to yield sufficiently accurate results was kept minimal. Nusselt numbers are presented and when possible, comparisons with results available in the literature are made. In addition, streamline and isotherm plots are presented to illustrate the physical nature of the flow field.