Defining Volume Fractions at an Inlet

For multi-phase flow analyses using the volume of fluid (VOF) method, you can specify the materials distribution flowing in the background fluid at the inlet. You can describe the material distribution using the volume of fluid fraction option or with the elevation option.

Before you begin: You must have your spatially mapped data prepared if you want to define any species with a concentration that varies in space. The mapped data should specify different concentration values at various points in space.
Note: When you define the mass fractions of individual species using spatially mapped data, you should confirm that the relative fractions add up to 1.0 in every location you specify. The app does not perform this validation.
See Also
About Inlets
In Other Guides
Support Selection
  1. Open the inlet for which you want to specify volume fractions.
  2. If you want to specify a uniform distribution in space for the secondary material in the VOF section, do the following:
    1. Select Uniform value from the distribution options next to the Volume fractions field.
    2. Enter a value (between 0.0 and 1.0) for the concentration of material.
  3. If you want to specify that the secondary material has a distribution in space that varies according to spatially mapped data, do the following:

    1. Select Mapped spatial data from the distribution options next to the Volume fractions field.
    2. Click Table.
      The Field Distribution dialog box opens, where you can enter or import the mapped concentration values.
    3. Choose the Data source for the mapped concentration values:

      • Table: Enter or import the mapped data into the table.

      • Referenced document: Select a 3DEXPERIENCE document that contains the mapping data. Click to search for the document in the 3DEXPERIENCE platform database. For details about the file format required, see Mapping Data File Formats.

        Changes in the referenced document are taken into account every time the simulation is run.

    4. If Data source is set to Table, specify the mapped data in the table:

      • To import the data, right-click anywhere in the table and select Import. For details about the file format required, see Mapping Data File Formats.
      • To enter the data manually, double-click in each cell and enter a value. For example, enter X-, Y-, and Z-coordinates and the corresponding concentration Value in each row of the table.

    5. Enter the Value outside the mapped region. This is a default concentration value.

      The simulation attempts to map all of the source data points and their associated concentration values onto points in the target model. For any target points where the simulation cannot map to a source point, it will substitute this default value.

    6. Select an Axis system definition for the coordinates of the mapped data values.

      • Global: Aligns the local feature triad with the global coordinate system.

      • Local: Aligns the local feature triad with a selected axis system in the model.

        Using a custom local axis system simplifies the three-dimensional definition of points in space—the X-, Y-, Z-coordinates are interpreted in the context of the local coordinate system.

    7. Select Plot Data to display symbols that indicate the locations and magnitudes of the mapped values on the model.

      Tip: If you click any row in the data table, the corresponding source point is highlighted on the model.

    8. To adjust the search control parameters, expand the Search tolerance.

      See Mapping Search Controls and Mapping Search Control Options for descriptions of these parameters.

    9. Click OK.
  4. Click OK in the dialog box.