HMCFD-T: 2000 Meshing

In this tutorial, you will cover the various meshing tools and options that are available in HyperMesh CFD. The five major mesh controls covered are:

  • Surface
  • Gap
  • Boundary Layer
  • Volume Mesh
  • Zones
Before you begin, copy the file(s) used in this tutorial to your working directory.
Figure 1.


Set Up Surface Mesh Controls

  1. Navigate to the Mesh ribbon.
  2. Click the Surface tool.
    Figure 2.


  3. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Group > shaft_small_impeller and small_impellers.
  4. In the microdialog, enter a value of 0.00125 for the average element size and set the geometric feature angle to 30.0.
  5. On the guide bar, click to execute the command and remain in the tool.
  6. Right-click on Surface mesh control (50) in the Surface controls legend and select Rename from the context menu. Rename the control to small_impellers or a suitable name of preference.
  7. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Group > shaft_large_impeller and large_impeller.
  8. In the microdialog, enter a value of 0.003 for the average element size and set the geometric feature angle to 30.0.
  9. On the guide bar, click to execute the command and remain in the tool.
  10. Right-click on Surface mesh control (27) in the Surface controls legend and select Rename from the context menu. Rename the control to large_impeller or a suitable name of preference.
  11. On the guide bar, click to execute the command and exit the tool.

Assign a Gap Control for the Whole Geometry

  1. Click the Gap tool.
    Figure 3.


  2. Right-click anywhere in the modeling window and select Show All to display all the solids of the geometry if they're not already visible.
  3. Press Ctrl + A or left-click and drag over the entire model to select all the surfaces.
  4. In the microdialog:
    1. Assign a value of 0.025 for Maximum gap between surface.
    2. Uncheck Restrict minimum gap.
    3. Select Points Across Gap for the refinement method.
    4. Assign a value of 4 for the Points across gap.
  5. On the guide bar, click to execute the command and exit the tool.

Set Up Boundary Layers on the Rotating Impellers

  1. Click the Boundary Layer tool.
    Figure 4.


  2. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Group > small_impellers.
  3. In the microdialog:
    1. Set the first layer thickness definition to Fraction of Surface Mesh Size.
    2. Set the total number of layers to 3.
    3. Choose a Constant growth method
  4. On the guide bar, click to execute the command and remain in the tool.
  5. Right-click on Boundary layer control (46) in the Surface controls legend and select Rename from the context menu. Rename the control to small_impeller or a suitable name of preference.
  6. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Group > large_impeller.
  7. In the microdialog:
    1. Set the first layer thickness definition to Fraction of Surface Mesh Size and the first layer thickness factor to 0.01.
    2. Set the total number of layers to 10.
    3. Choose a Constant growth method
  8. On the guide bar, click to execute the command and remain in the tool.
  9. Right-click on Boundary layer control (25) in the Surface controls legend and select Rename from the context menu. Rename the control to large_impeller or a suitable name of preference.
  10. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Group > interface_large_impeller.
  11. In the microdialog:
    1. Set the first layer thickness definition to Fraction of Surface Mesh Size and the first layer thickness factor to 0.5.
    2. Set the total number of layers to 1.
    3. Choose a Constant growth method
  12. On the guide bar, click to execute the command and remain in the tool.
  13. Right-click on Boundary layer control (8) in the Surface controls legend and select Rename from the context menu. Rename the control to large_impeller_interface or a suitable name of preference.
  14. On the guide bar, click to execute the command and exit the tool.

Assign Volume Mesh Controls to the Small Impellers

  1. Click the Volume Mesh tool.
    Figure 5.


  2. Right-click anywhere in the modeling window then pick Select > Advanced Select > By Solid Bodies > Small impeller 1 and Small impeller 2.
  3. In the microdialog, set the average size to 0.00125
  4. On the guide bar, click to execute the command and exit the tool.

Create a Refinement Zone for the Mixing Domain

  1. From the Zones tool group, click the Cylinder tool.
    Figure 6.


  2. Snap the cylindrical zone to the center of the shaft as shown in Figure 7. Drag your mouse and click anywhere on the screen to define a temporary size for the cylinder. In the radius microdialog, enter a value of 0.54 and press Enter.
    Figure 7.


  3. In the new microdialog, enter a value of 1 for the Height (H) dimension.
  4. Click on the white arrow pointing in the Y direction to move the zone along the Y-axis.
  5. Enter a value of -0.86 then press Enter to move the zone along the negative Y direction.
    Figure 8.


  6. Enter a value of 0.0025 for the mesh size.
    Figure 9.


  7. Press Esc to exit the tool.

Run a Surface/Volume Batch Mesh

  1. Click the Volume tool.
    Figure 10.


  2. Set a value of 0.005 for the Average element size.
  3. Check Generate boundary layers on fluid domains only.
  4. Click Mesh to execute the batch mesh process.
    Figure 11.