In the Constituent Materials tab, the Invading Fluid and the Displaced Fluid can be entered.

If the phase distribution under the Wetting Parameters tab is chosen by Pore Size, the displaced fluid must be present in the structure and can be chosen from the drop-down menu. If the phase distribution is taken from Simulated Wetting Process, then both fluids are defined by the capillary pressure curve result file.

No more settings need to be done as the diffusivity is always set to 1.