Three options for the Contact Angle Mode are available:

1. Constant Contact Angle: For the Pore Morphology method, a single (constant) contact angle is assumed between all solid materials and the invading fluid, and another constant contact angle between all solid materials and the displaced fluid. The given contact angle is considered for the computation of the capillary pressure in the post processing, but a contact angle of 0° is used for the distribution of the fluids!
2. Multiple Contact Angle: For a more general Pore Morphology method, different (multiple) contact angles are specified for every solid material with the invading fluid and the displaced fluid. The contact angles of every material can be entered under the Contact Angle tab on the right-hand side below. The different contact angles are considered for the computation of the capillary pressure and for the distribution of the fluids. Surfaces of solid materials are assumed to be planar for this approach.
3. True Contact Angle: In this default setting, the same way as for Multiple Contact Angle, contact angles for every solid material with the invading and the displaced fluid can be defined. To inscribe fluids with a more accurate contact angle, the curvature of the surface of solid materials is considered. For contact angles near 90°, the artefacts occurring for the Multiple Contact Angle method are avoided.

Enter the Interfacial / Surface Tension in N/m between the invading and displaced fluid or use the default value of 0.07275 N/m corresponding to the surface tension between water and air at 20°C.

The Invading Fluid invades the current structure and displaces the Displaced Fluid. The invading fluid can be selected through the Material Selector dialog box, by clicking on the button for the material.

The pull-down menu gives access to selecting the desired material from the GeoDict Material Database. When none of the materials available in the database fit the preferred specifications, Manual should be chosen. Alternatively, a new material with the desired specifications can be added to the Material Database (see the Material Database chapter).

To match realistic material colors for visualization in a certain application, the default material colors can be changed through the Color & Visibility tab of the GUI sidebar. For more visualization options, see the Visualization chapter.

The Displaced Fluid must already be present in the model of the structure currently in memory. Choose the displaced fluid from the drop-down menu. To change the fluid to another one, select a different fluid in the Material panel below. The changes apply automatically to the selection in this menu.

Important! For materials with different material laws, the selection of a material law is not updated. In this case, you have to choose the material law manually from the drop-down menu.

Set the Temperature applied for the calculation in the selected units below. Click Open & Edit Material Database to edit the material properties in the Material Database if needed.

Underneath, the Material panel contains the Material IDs of the constituent materials present in the current structure. By default, Material IDs that are not present in the structure are not displayed under the Material tab, but they can be displayed by clicking on the “+” symbol to the left of the Material tab. Click on the name of a material to change the material of the corresponding Material ID in the Material Selector as explained above for Invading Fluid.

Click the Material Report button to see the relevant parameters for the material.

In the Fluid Density / Viscosity panel you can see the physical properties density and viscosity of the fluids in the structure. If available, you can select between different material laws. For manual materials, define their properties directly in this panel.

In the Contact Angle panel, enter the contact angle for all solid materials (after choosing Constant Contact Angle as Contact Angle Mode) or for each solid material separately (after choosing Multiple Contact Angle or True Contact Angle as Contact Angle Mode). For fluids, it will be displayed if it has a role in the simulation, e.g. in this simulation Water will be displaced.

The Invading Fluid CA (Contact Angle) and the Displaced Fluid CA values add up to 180° and they are adjusted automatically when changing one of the two values. For a given solid material phase, the fluid with a contact angle smaller than 90° is wetting and the other fluid (with contact angle larger than 90°) is non-wetting.