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CHAPTER 8
EFFICIENT FULLY IMPLICIT SCHEME FOR
MODELING OF ADSORPTIVE TRANSPORT;
(PARTIALLY-) SATURATED CONDITIONS
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Ralph Waldo Emerson
Abstract
Pore network modeling has been widely used to study variety of flow and transport
processes in porous media. To do so, equations of mass balance should be
discretize to be used within network elements. Different formulations of solute transport
within the pore-network model have been introduces in the literature for the
case of saturated conditions. However, there are much less studies under partially
saturated conditions. Under partially saturated conditions the system contains three
phases: air, water, and solid. The principal interactions usually occur at the solidwater(SW)
interfaces and air-water(AW) interfaces, thus greatly influenced by water
content. In this chapter, we introduce a fully implicit numerical scheme for transport
of adsorptive solute under (partially-) saturated conditions, undergoing both/either
equilibrium and/or kinetic types of adsorption. We have considered absorption to
the SW as well as AW interfaces.
The numerical scheme is developed based on
the assumption that porous media is composed of a network of pore bodies and pore
throats, both with finite volumes. While under saturated conditions we have assigned
one concentrations to a pore body or pore throat, under unsaturated conditions we
assign separate concentrations to each edge of a drained pore body or pore throat.
Through applying an efficient numerical algorithm, we have reduced the size of system
of linear equations by a factor of at least three, which significantly decreases the