Basic 3D-CAD: Define Fluid Volume for Rotating Fan and Subtract the Blades

Modeling anything with a moving part, such as the graphics card fan, requires at least two simulation regions. One region rotates to model the motion of the fan, while the other region remains stationary to represent the remaining air. Here, you create the rotating region in 3D-CAD.

To create the rotating region:

  1. Launch Simcenter STAR-CCM+ and load foundationTutorial_5.sim.

    You can either use the sim file that you saved from the previous tutorial, or load the sim file provided in the tutorials bundle. See Downloading the Tutorial Files from the Support Center Portal.

  2. Save the simulation as foundationTutorial_6.sim.
  3. Resume the 3D-CAD model.
  4. Draw a sketch around the fan:
    1. Select the bottom face in the cavity of the enclosure, as shown below, and select Face > Create Sketch > On Face.


    2. Make the view normal to the sketch plane and make the geometry transparent.
    3. Draw a circle with a radius of 47 mm and centered around the origin.


    4. Click OK to complete the sketch.
    5. Rename Features > Sketch 1 to Rotating Region Outline.
  5. Create the body for the rotating region:
    1. Right-click Rotating Region Outline and select Extrude.
    2. Set Direction Type to Reverse.
    3. Set Distance to 35 mm.
    4. Set Body Interaction to None to create a separate body from this operation.
    5. Click OK.
    6. Rename Features > Extrude 1 to Rotating Region.
    7. Expand the Body Groups node and rename the new body to Rotating Region.
  6. Create a copy of the rotating region to subtract from the static region in the next section:
    1. Right-click Body Groups > Rotating Region and select Duplicate.
    2. In the Duplicate Bodies panel, click OK.
    3. Rename Body Groups > Rotating Region 2 to Disc.
    4. Rename Features > DuplicateBody 1 to Duplicate Rotating Region.
  7. Subtract the fan and enclosure from the rotating region:
    1. Within Body Groups, multi-select the Enclosure, Fan and Rotating Region nodes.
    2. Right-click on a selection and select Boolean > Subtract.
    3. In the Subtract panel, make sure that Target Bodies is set to Rotating Region and Tool Bodies is set to Enclosure and Fan.
      To change the selections, click inside the relevant group box and select the desired body from the 3D-CAD View scene or use the 3D-CAD feature tree. Target bodies are displayed in green while tool bodies are displayed in red.
    4. Activate Keep Tool Bodies to keep the tool bodies after performing the operation.
      By default, all tool bodies are absorbed by the operation. If you want to keep the bodies for visualization or simulation purposes, activate this option.
    5. Click OK to perform the subtraction.
    6. Rename Features > SubtractBodies 1 to Subtract Fan and Enclosure.
  8. Rename the outer faces of the rotating region body:
    1. In the 3D-CAD feature tree, expand the Body Groups node.
    2. Right-click the Rotating Region body and select Show Only.
      All bodies other than the selection are hidden in the 3D-CAD View scene.
    3. In the 3D-CAD View scene, select the large top and side faces in the scene. Do not select the faces in the narrow gap or the bottom face.


    4. Right-click a selection and choose 3 Faces > Rename.
    5. In the Rename dialog, enter Interface and click OK.
      The selected faces are renamed. These faces are listed under the Body Groups > Rotating Region > Named Faces node. From here, you can rename or delete the custom name if you desire.
    6. In the Body Groups > Rotating Region > Named Faces node, rename the Default node to Fan.
  9. Rename the outer faces of the disc body:
    1. In the 3D-CAD feature tree, right-click the Disc body and select Show Only.
    2. In the 3D-CAD View scene, select the top and side faces in the scene. Do not select the bottom face.


    3. Right-click a selection and choose 2 Faces > Rename.
    4. In the Rename dialog, enter Interface and click OK.
      The selected faces are renamed. These faces are listed under the Body Groups > Disc > Named Faces node.
    5. In the Body Groups > Disc > Named Faces node, rename the Default node to Base.
  10. Right-click a blank space in the 3D-CAD View scene and select Restore > Hidden Bodies.


  11. Save the simulation.