# Density of Liquid Phase in Porous Media#

Density of liquid phase in porous media = {yes | no}


## Description / Usage#

This post processing option can be used to trigger the computation and output of the density of solvents in the liquid phase only, averaged over the mixture, as a nodal field variable to the output EXODUS II file. The nodal variable is called Rho_Liq_Phase. The mathematical details are given below in the technical discussion. This option applies to media types of POROUS_SATURATED, POROUS_UNSATURATED, and POROUS_TWO_PHASE (see Media Type card). The options are:

 yes Calculate and write the density of solvent in the liquid phase as a postprocessing variable to the output EXODUSII file. no Do not calculate the liquid solvent density.

## Examples#

An example of an input card which activates writing of the density to the EXODUS II file is:

Density of liquid phase in porous media = yes


## Technical Discussion#

In liquid-saturated flow cases, viz. for Media Type selection POROUS_SATURATED, the total solvent density in the liquid phase is

where $$\rho_l$$ is the pure liquid density and $$\phi$$ is the porosity. Here we have assumed that no liquid solvent is adsorbed into the solid struts (currently the assumption used throughout Goma).

For partially saturated flows, viz. for Media Type selection POROUS_UNSATURATED or POROUS_TWO_PHASE, the density of solvent in the liquid phase only is given by

where S is the saturation (see Porous Saturation card). Compare this with the quantity computed with the Total density of solvents in porous media card.

## References#

GT-009.3: GOMA’s Capabilities for Partially Saturated Flow in Porous Media, September 1, 2002, P. R. Schunk