Transient natural convection between two vertical walls filled with a porous material having variable porosity

被引：0

作者：

Paul, T. ^{[1
]}

Singh, A.K. ^{[1
]}

Mishra, A.K. ^{[1
]}

机构：

[1] Department of Mathematics, Banaras Hindu University, Varanasi-221005, India

来源：

| 2001年 / VSP BV卷 / 08期

关键词：

Computer simulation - Heat convection - Mathematical models - Matrix algebra - Method of moments - Porosity - Porous materials - Prandtl number;

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摘要：

This paper analyses the effects of variable porosity and inertial force on free convective flow between two vertical walls filled with a porous material. The Brinkman-Forcheimer-extended Darcy model is used to simulate the momentum transfer in the porous domain. A numerical scheme for the transient solution of the governing equations is devised to investigate the channelling effect on the velocity field due to variable porosity of the porous matrix. The finer grid points taken near the walls have revealed that the influence of variable porosity is significant only near the heated wall. A series of the numerical experiments indicates that the flow depends on time for the considered values of diameter of the spherical beads and becomes steady state when the value of non-dimensional time is close to the Prandtl number of air. It is found that the Darcy model predicts an enhancement in the air velocity near the heated wall compared to the general flow model. Formation of the boundary layer near the heated wall is a result of the Brinkmann term and its effect is strongly dependent on the diameter of the spherical beads.

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