Abstract: This paper presents the heat and mass driven natural
convection succession in a Darcy thermally stratified porous medium
that embeds a vertical semi-infinite impermeable wall of constant
heat flux and concentration. The scale analysis of the system
determines the two possible maps of the heat and mass driven natural
convection sequence along the wall as a function of the process
parameters. These results are verified using the finite differences
method applied to the conservation equations.
Abstract: This paper reports the numerical simulation of doublediffusive
natural convection flows within a horizontal annular filled
with a saturated porous medium. The analysis concerns the influence
of the different parameters governing the problem, namely, the
Rayleigh number Ra, the Lewis number Le and the buoyancy ratio N,
on the heat and mass transfer and on the flow structure, in the case of
a fixed radius ratio R = 2. The numerical model used for the
discretization of the dimensionless equations governing the problem
is based on the finite difference method, using the ADI scheme. The
study is focused on steady-state solutions in the cooperation situation.
Abstract: Considering the numerous applications of the study of
the flow due to leakage in a buried pipe
in unsaturated porous media, finding a proper model to explain the
influence of the effective factors is of great importance.There are
various important factors involved in this type of flow such as: pipe
leakage size and location, burial depth, the degree of the saturation of
the surrounding porous medium, characteristics of the porous
medium, fluid type and pressure of the upstream.In this study, the
flow through unsaturated porous media due to leakage of a buried
pipe for up and down leakage location is studied experimentally and
numerically and their results are compared. Study results show that
Darcy equation together with BCM method (for calculating the
relative permeability) have suitable ability for predicting the flow due
to leakage of buried pipes in unsaturated porous media.