Setting Up the Phase Interaction

Phase interactions describe the mutual influence of the two materials (phases) air and water on each other. In this simulation, you activate the surface tension force model to enable the computation of surface tension effects between phases in the phase interaction. To enhance stability for larger time-steps, you activate Semi-implicit Surface Tension. Once enabled, the momentum source term due to surface tension is calculated in a semi-implicit way.

When you create a phase interaction, you select the primary phase first, and then the secondary phase. In this simulation, the primary phase is Water and the secondary phase is Air.

To define the phase interaction:

  1. In the Physics 1 continuum, right-click the Models > Multiphase Interaction > Phase Interactions node and select New > Water > Air.
  2. Rename the Phase Interaction 1 node to Surface Tension.
  3. For the Surface Tension phase interaction, select the following models:

    Group Box

    Model

    Optional Models

    Surface Tension Force

    Multiphase Material (selected automatically)

  4. Click Close.

The default surface tension value for the water-air interface, 0.072 N/m, is appropriate for this simulation.

  1. Edit the Surface Tension > Models node and set the following properties:
    Node Property Setting
    Multiphase Material > Material Properties > Surface Tension > Constant Value 0.072 N/m
    Surface Tension Force Semi-implicit Surface Tension Activated
  2. Save the simulation.