Mesh the Model

Specify the mesh techniques and parameters for meshing the fluid domain and solid parts.

Hexahedral-dominant ("hex-dominant") meshes contain primarily linear hexahedral (hex) elements and produce the most accurate results for simulations of 3D models. Computational fluid dynamics (CFD) simulations use hex-dominant meshes because they mesh 3D fluid domains and allow the addition of boundary layers, useful for capturing transient effects in fluid flow near walls. A sweep 3D mesh generates a uniform mesh throughout the model and achieves good convergence for fluid simulations.

In this example, you first use a hex-dominant mesh to mesh the CPU enclosure while ignoring sharp edges in the model. You then create sweep 3D meshes for the heat sink and the chip to generate a uniform mesh throughout the CPU board. Finally, you check the total number of elements and nodes in the created mesh.

This task shows you how to:

Mesh the CPU Enclosure

  1. From the Standard section of the action bar, click Mesh .
    The model opens in Mesh Creation.
  2. From the Mesh section of the action bar, click Hex-Dominant Mesh .
  3. Enter a maximum size of 6 mm and a minimum size of 0.4 mm.

    This represents the global element edge sizes.

  4. Enter a minimum angle between faces of 30deg.

    This represents the smallest angle between geometric faces that will result in an edge between element faces.

  5. Select Add boundary layers.
  6. Enter a first layer thickness of 0.1 mm, and set the number of layers to 3.
  7. Click Mesh, and then click OK.

    Tip: From the tree, right-click Finite element model > Nodes and Elements and click Hide/Show to show the mesh.

    The hex-dominant mesh on the CPU enclosure is shown below. This represents the fluid mesh.

  8. Optional: View the mesh along different cutting planes by doing the following.
    1. From the Display section of the action bar, click Sectioning .
    2. Clear the Exact mesh cut selection.
    3. Drag the cutting plane in the 3D area to change the location of the cut.

      The default cutting plane is the X-axis.

    4. Select Y-axis and Z-axis to view the mesh along other cutting planes.
    5. Click Close.

Mesh the Heat Sink and Chip

  1. From the Mesh section of the action bar, click Sweep 3D Mesh .
  2. From the tree, select the heat sink as the support.
    The heat sink is highlighted.
  3. Enter a mesh size of 0.25 mm, and set the number of layers to 16.
  4. Click Mesh, and then click OK.
  5. Similarly, create a sweep 3D mesh for the chip with a mesh size of 2 mm and 8 layers.

    The applied sweep 3D mesh on the heat sink and chip is shown below.

  6. From the Mesh section of the action bar, click Mesh Part Manager .
  7. Click on each row to hide the meshes.
  8. Click OK.

Check the Mesh Count

  1. From the Check section of the action bar, click Quality Analysis .
  2. From Types, note the quantities for the Total number of nodes and Total number of elements.

    Computational time is proportional to the total number of elements created.

  3. Click OK.
  4. Save your work.