Initial Condition and Source

The Initial Condition and State are volume conditions in the Cavitation module pertaining to selected Volumes. Specify Initial Condition and State in Cavitation module as follows:

Geometric Entities Panel > Volumes > [Desired Volume]
Properties Panel > Model Tab > Cavitation > (Initial Condition or State)

Initial Condition

Initial Condition refers to the values of the independent variables used to start a simulation when Start from Initial Values is selected in the Simulation Panel. For selected volumes, the condition is input under Specified Value. In this module, the variables requiring initial values, which depend on the Cavitation models, are listed in Table 5.18.

Figure 5.72 - Initial condition

Models for NCG	Gas Mass Fraction	Vapor Mass Fraction	Dissolved Gas Mass Fraction
Constant Gas Mass Fraction	No	Yes	No
Equilibrium Dissolved Gas Model	No	Yes	No
Variable Gas Mass Fraction	Yes	Yes	No
Dissolved Gas Model	No	Yes	Yes
Full Gas Model	Yes	Yes	Yes

Table 5.18 - Cavitation initial conditions

Note: The alternative to using Initial Condition to start a simulation are the options: Start from Solution or Continuation Run. In such cases, the Initial Conditions specified are not used.

State

The State of a Volume within the Cavitation module determines whether Cavitation is solved (Active) or not solved (Blanked) within the specified volume. Cavitation within a Blanked volume will be left as the Initial Condition.

Figure 5.73 - State

Source

The Source is a volume condition in the Cavitation module pertaining to selected Volumes. To specify the source, click Create a New Source (see Figure 5.74) in the Cavitation module as follows:

Geometric Entities Panel > Volumes > [Desired Volume]
Properties Panel > Model Tab > Cavitation > Create a New Source

Table 5.19 lists the potential sources terms that can be added in the respective modelling equations:

Figure 5.74 - Create a new source

Cavitation Module VC Properties	Comments
Source
Free Gas Source	Add a source/sink of the non-dissolved (Free) NCG to a selected volume. Available for the Dissolved Gas Model, Equilibrium Dissolved Gas Model, Full Gas Model and Variable Gas Mass Fraction model.
Vapor Source	Add a vapor source/sink to a selected volume. Available for all Cavitation models.
Dissolved Gas Source	Add a source/sink of dissolved NCG to a selected volume. Available for Dissolved Gas Model and Full Gas Model.

Table 5.19 - Volume conditions parameters

Multiple sources may be created for a selected volume. Sources may be added as a Total Source (kg) or a Source per Volume (kg/m³).

Remove This Source

This input removes the Source in a selected volume.

Note: If no source has been created, the Source heading is not displayed. Multiple sources are numbered sequentially, e.g. Source 1, Source 2, Source 3, etc. If a source is removed, the remaining sources are renumbered starting at 1.