WIT Press


The Influence Of Variable Viscosity On Thermal Convection In Porous Media

Price

Free (open access)

Paper DOI

10.2495/HT980121

Volume

20

Pages

10

Published

1998

Size

955 kb

Author(s)

E. Holzbecher

Abstract

Convective motions in porous media are relevant in studies on geothermal systems, in thermodynamics, in chemical engineenng and for several industrial purposes. Density differences in a fluid system induce convection if they exceed a critical margin. The criterion is mostly formulated in terms of the dimensionless Rayleigh-number and is derived under the assumption of constant viscosity. In the paper it is shown that the critical Rayleigh-number is substantially reduced if variable viscosity is also taken into account. The reduced numerical value of the margin is determined by numerical modeling using the FAST-C(SD) code for simulation runs on the computer. The result is relevant for convective motions in real systems because the re

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