Specify Fans

Identify the components that represent fans in the model.

Fans are modeled like wheels, a boundary condition is prescribed and a rotational speed is applied.

Select the parts that form the fan, such as blades and hub. The center and axis of rotation are automatically computed. However, the rotational speed needs to be provided. Virtual Wind Tunnel for ultraFluidX supports three approaches for fans: Frozen, MRF, and Overset. In Frozen or MRF models, the fan does not rotate in the simulation. An MRF volume improves modeling of the swirling flow created by a fan. To simulate a truly rotating fan, use an Overset mesh model. With an Overset volume, the fan and mesh inside is rotated to accurately represent the flow and rotating fan.

  1. From the ultraFluidX ribbon, Setup group, click the Identify Parts tool.

    Figure 1.
  2. From the secondary tool set, click the Create Fans tool.

    Figure 2.
    The Fan dialog opens.
  3. Select a part to define as the fan.
    The Axis and Speed automatically populate based on the part selection.
  4. Optional: Adjust the Axis and speed.
  5. Select the Fan Model from the following options:
    • Frozen
    • Overset
    • MRF
  6. If Frozen is selected for Fan Model, skip to step 12.
    Important: Steps 7 - 9 are only relevant for Overset and MRF fan models. Steps 10 and 11 are only relevant for Overset.
  7. Create a volume around the fan by completing one of the following:
    Choice Selection
    Import a previously created volume
    1. Select Select.
    2. Browse, select, and import the previously created volume.
    Create a cylinder volume
    1. Select Cylinder.
      A tightly wrapped cylinder volume is automatically created around the fan.
      Tip: You can adjust the size of the cylinder by selecting the diameter or height labels in the modeling window and entering a new value in the microdialog.

      Figure 3.
    Create a Solid Revolution volume
    1. Select Solid Revolution.
      A CAD geometry is automatically created around the fan.
      Tip: You can adjust the offset size by entering a new value for Offset. If the Offset is too large, a warning will be given.

      Figure 4.

      Figure 5.
  8. Optional: To check for and split intersecting parts, enable the Split Intersecting Part checkbox.
    A color coded legend displays which indicates any intersecting, interior, and exterior parts. When the fan is created, the intersecting parts are split.

    Figure 6.
  9. Adjust the Refinement Level.
    The Element Size will be adjusted automatically.
  10. Enable the Interface Refinement checkbox, to refine the interface of the Overset volume.
  11. Adjust the Refinement Level of the interface refinement.
    The Element Size will be adjusted automatically.
  12. Complete one of the following:
    • Select to confirm your selections and continue specifying fans.
    • Select to confirm your selections and exit the dialog and tool.
    • Select to clear your selections and start over.
    • Select to exit the tool without confirming your selections.