Re: Porous Media

["David L Parkhurst" <dlpark@xxxxxxxx>]

>    I am an engineer (in a french company) and I am looking for a
numerical code able to solve reactive (species diffusion + chemical
reactions) Fluid Mechanics equations (integrated over a representative
volume) in the case of a porous medium (carbon fiber or something like
that) which undergoes a gaseous chemical treatment at low pressure.

We do not have any 2-phase transport models, where both the liquid and the
gas phase are mobile. However, PHREEQC is a 1D reactive transport model
that may useful (https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc or
http://water.usgs.gov/software). PHREEQC can model reactions in either a
well mixed reactor, or in 1D transport with a mobile water phase
(essentially a series of well mixed reactors). It is possible to model
gas/water reactions as either fixed partial pressures or a fixed-volume or
fixed-pressure gas phase in equilibrium with the water; however, the gas
phase is not mobile, but remains in contact with a specified cell. It is
also possible to add the gaseous reactants as a specified reaction, where a
specified amount of reactant is added to the reactor. Kinetic reactions are
also possible, where the rate of addition (or consumption) of the
reactant(s) is specified.

>    Do you know if that kind of code exist? And can softwares like USGS
MODFLOW (or another USGS's software) be used (after a few modifications)
to solve that kind of problem?

Modflow has no transport capabilities. There is a code MT3D, based on
Modflow, that calculates solute transport, but only has very simple
reaction capabilities. A 3D reactive transport code based on PHREEQC is
available in beta test (version 0.3 should be available shortly,
https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phast), but again the gas
phase is subject to the same limitations as PHREEQC, where the gas phase is
not mobile.

David

David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225