Generating hexahedral mesh and inflation on pipe system

    • habibulaqil97

      Hello everyone,

      I am an intern studying and still a newbie about ANSYS simulations and I would like seek a kind assistance regarding my meshing process of my pipe system. Below are my pipe system consists of pipes, reducers, reducing tees and elbows:Pipe system

      Now I was asked by my supervisor to generate hexahedral meshes and inflation layers on my pipe system. So far I have tried using sweep (manual src/trg because I need to add inflation layers on sweepable bodies) and hexa dominant methods. However, I was unable to generate both hexahedral meshes and inflation layers due to multiple reasons:

      • When I apply sweep method, all of my pipe bodies can be applied with sweep method which lead to hexahedral elements to be generated except the parts where they are connected with mixing tees. Below are (green) bodies which are sweepable:

      • I tried applying inflation method on the parts where sweep method is viable but every time I try to generate inflation layers, the method is found to be invalid, therefore inflation layers cannot be created. Same issues occured when I try to inflate hex dominant meshed bodies.

      I hope anyone can help me as soon as possible and if there are any inquiries about my problems, please do ask me.

    • Karthik R

      Are your bodies sweepable? Please right click and ask Meshing to display sweepable bodies. If it does not display all of your geometry, you will not be able to generate a Hex mesh. To obtain a hex mesh, you will need to further decompose your geometry to get sweepable bodies.

      Regarding inflation layers, could you please try using the Multizone approach (rather than Sweep) and try to apply the inflation settings?

      Please let me know if this works for you.



    • habibulaqil97

      Hello Kremella,

      Thank you for replying. I have shown the bodies that are sweepable above which is colored in green, and the areas that are connected with mixing tee are apparently not sweepable.

      I have tried using multizone on the areas that aren't colored in green but the error "multizone blocking decomposition failed". Is this means I need to further split these bodies in DM as well?

      Let me know what you think.



    • Rob
      Ansys Employee

      The T-junctions can be hexed but I'd not bother trying now, just use tet elements.  Also, we may want a predominantly hex mesh but do not use the "hex-dominant" meshing method it's for Mechanical and the CFD solvers won't run on it. 

      My suggestion would be to inflate the faces of interest on the T-junction parts using one inflation setting (number of layers must be identical for all parts). Mesh of of the T-junction volumes then work through the rest of the domain volume by volume. You'll get a mix of tets and swept prisms which will solve the problem nicely.  You may then need to review the mesh and redo some of it, but that's part of the learning process. 

    • Keyur Kanade
      Ansys Employee

      First clear the mesh

      then create hex mesh with inflation. 

      use same inflation settings for the remaining bodies 

      then generate tet mesh. 




      If this helps, please mark this post as 'Is Solution' to help others.

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