Specifying a Cell Network with Partially Saturated Porous Media

The CellNet generator can be used to create a Cell net representing a partially saturated porous medium system. In most cases, this will be a system that is partially saturated with water (with the second fluid being air).

To create such a system, you must:

• Specify a Vol. Frac. (i.e., saturation) for the first Fluid of less than 1; and

• Specify a second Fluid (in the Fluid2 column).

In most cases, the first Fluid will be water, and the second Fluid will be air.

The second Fluid is assumed to fill any remaining pore space in the Cell (i.e., the first Fluid is assumed to be the wetting fluid).

By specifying Darcy velocities when defining the zones, the CellNet will create advective connections in the first Fluid (typically water).

If you check the Create diffusive links checkbox, GoldSim will create diffusive links for both fluids. That is, if you defined the first Fluid as water and the second Fluid as Air, GoldSim would create a Cell net with both aqueous and gaseous diffusive connections.

Note: To accurately simulate diffusion through partially saturated porous media, it is important that you define a Diffusive Reduction Formula for each Fluid that varies with saturation. Note that when automatically generating diffusive connections using a CellNet Generator, the saturation level for the fluids is defined directly by the user (via the Vol. Frac. input), as opposed to being computed internally by GoldSim as a function of specified volumes.