Define Turbulence Source Regions

Use the Turbulence tool to generate turbulence source regions.

Turbulence source regions introduce randomly placed eddies on a user-defined plane to create turbulence in the smooth, incoming flow to mimic realistic flow disturbances. This can improve the drag coefficient prediction.
  1. From the Setup ribbon, click the Turbulence tool.
    Figure 1.


  2. In the modeling window, select a part on which you would like to place the turbulence source.
    A turbulence source consisting of a turbulence generating plane and a mesh control box is created.
  3. Re-size the mesh control box by completing one of the following:
    • Click and drag a face of the mesh control box.
      Figure 2.


    • In the microdialog, click and adjust the Length, Width, and Height.
    Note: Resizing the mesh control box automatically re-sizes the plane.
  4. Click and use the graphical manipulators to move the turbulence source.
    Figure 3.


  5. Optional: In the microdialog, click and define turbulence source region settings.
    1. Set the Turbulence Intensity.
      This controls the intensity of the eddies created on the turbulence plane.
    2. Adjust Refinement Level of the mesh box.
      The element size that corresponds to this refinement level is shown below.
      Note: The refinement level automatically adjusts the default values for Plane Offset, Eddy Length Scale, and Number of Eddies.
    3. Adjust the Plane Offset to adjust the gap between the turbulence source plane and box.
    4. Adjust the Eddy Length Scale.
      This controls the size of the eddies generated on the turbulence plane.
    5. Adjust the Number of Eddies.
      This is the total number of eddies generated on the turbulence plane. Eddies are placed randomly on the plane.
    Figure 4.


    Tip: After changing a value in the microdialog, click next to the edited value to reset it.
  6. Optional: Use a turbulence source without mesh control.
    1. In the microdialog, disable the Mesh Control check box to remove the mesh control box.
    2. Click an edge of the plane and use the graphical manipulators to re-size the selected edge.
      Figure 5.


    3. Click and use the graphical manipulators to move the plane.
      Figure 6.


  7. From the guide bar, complete one of the following:
    • Select to confirm your selection and continue creating turbulence source regions.
    • Select to confirm your selection and exit the tool.