Initial Values
Use the Initial Values node to define the initial values of the phase field variable.
Initial Values
The initial positions of the two fluids, and consequently the fluid-fluid interface, can be specified in two ways. The phase field variable can be specified explicitly, using any type of variable or expression. Alternatively the fluid occupying the current domain selection can be specified. Using the former method, a Time Dependent study step can directly be solved. Using the latter method, a Phase Initialization study step is needed in order to initialize the phase field function across the fluid-fluid interface.
Specify the Phase field variable as one of the following:
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To specify the fluid occupying the domain, select Specify phase (default). Then select the check box Fluid 1 () or Fluid 2 ().
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For User defined enter a value or expression for the phase field variable .
If the Phase Initialization () study step is being used, for the initialization to work it is crucial that there are two Initial Values nodes. One of the Initial Values nodes is set to Specify phase: Fluid 1 () and the other to Specify phase: Fluid 2 (). The initial fluid-fluid interface is then automatically placed on all interior boundaries between both phases. The smooth initialization is not used in domains with User defined initial values.