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Tet-Dominant algorithm: Pipe-flow meshing tutorial

This meshing tutorial demonstrates how the Tet-Dominant meshing algorithm can be used to generate high-quality meshes for internal flows.

Link to tutorial project containing the geometry:

Go to tutorial project

1) Copy project with CAD model

  • Click on the project link above which brings you to the project overview page of the tutorial project.

  • On the top right corner click on Actions and select Make a copy

  • In the opening dialog you can change the title of the project or its description

  • Click on Copy project to create a copy in your personal dashboard (this operation could take a few seconds)

  • After successful copy you will see the new project appearing in you dashboard. Hover over the project and click on the appearing arrow on the top right corner of the project thumbnail to directly open the project.

  • Once the project is loaded, you should see the bearing block geometry in the viewer

  • Use the Geometry Event Log to check on the dimension of your CAD file

    Geometry of the pipe flow fluid domain

    Geometry of the pipe flow fluid domain

2) Creating a new mesh

  • Create a new mesh with the uploaded geometry by clicking New Mesh button
  • In the newly created mesh, the CAD geometry serves as its base

3) Choosing the mesh type

  • Once the mesh operation is created, choose the desired type - in this case we want to apply the Tet-dominant algorithm.

4) Defining the operation parameters

  • In the propertires of the meshing algorithm, leave the Element sizing to be automatic, but change the Mesh fineness from 2 - coarse to 4 - fine in order to reduce the overall element size uniformly.

    Global settings for the pipe flow mesh

    Global settings for the pipe flow mesh

  • In order to correctly model the flow through a pipe the boundary layer has to be resolved accurately. This can be achieved by refining the mesh in the regions close to the walls. The best method to do this is by the help of a layer inflation mesh refinement. To add a mesh refinement, click on New on the lower left side of the mesh settings panel next to Mesh refinements.

  • In the mesh refinements settings, change the type from local element size to layer inflation. Change the total layer thickness to \(0.01\) m and leave the rest of the settings as the default values.

  • Now the areas need to be defined where the layer refinement should act on. For this, first select all wall faces of the pipe (all faces besides the three circular ones) and click on Add selection from viewer to assign them to the layer refinement. Hit Save to store the setup.

    Setup of the layer inflation mesh refinement on the wall faces

    Setup of the layer inflation mesh refinement on the wall faces

Important

If the a mesh created with the Tet-dominant meshing algorithm should be used later for a fluid mechanics analysis a first order mesh has to be used, otherwise the CFD solver can not handle the mesh.

5) Start the mesh operation and examine the mesh

  • Go the the mesh operation (by default called Operation 1) and click on the Start. Check the notification area on the lower left for status information.

  • Once the operation is finished the viewer will be updated with the mesh.

    Resulting mesh with layer refinement on wall faces

    Resulting mesh with layer refinement on wall faces

  • In order to investigate also the internal mesh, a mesh clip can be applied:

    How to add a mesh clip

    How to add a mesh clip

  • Leave the default settings and click on apply. Now the internal mesh is visible and it can be checked that the layer mesh has correctly been created on all of the wall faces.

    Detailed view on clipped mesh

    Detailed view on clipped mesh