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

Keywords