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-   -   [ICEM] How to make Pereodic Tetra mesh? (https://www.cfd-online.com/Forums/ansys-meshing/81972-how-make-pereodic-tetra-mesh.html)

ale-kc November 12, 2010 03:04

How to make Pereodic Tetra mesh?
 
Hello!
I am beginner in ICEM CDF. I've task to mesh square heat exchanger(complex geometry) with pereodic condition at left and right side.
The question is how to make pereodic mesh at left and right faces?

I've tried to use Tetra mesh method Robust (Octree) but the results was very poor quality of mesh with bad shape elements at left and right faces (but they absolutely pereodic).

Can I do the pereodic mesh using another way in ICEM CFD?
for example at first to prepare pereodic shell mesh at left and right faces with good mesh quality (how to do it?) then using Smooth (Advanced front) to prepare tetra mesh.

Thank you

PSYMN November 14, 2010 21:21

Periodicity
 
You set up periodicity on the Mesh Tab => Global Mesh Parameters (It is the last icon in the DEZ).

Sorry, your email was unclear, is that what you did?

The above method with Octree is the easiest way... It also works with Hexa Blocking, although you must take it one more step and assign the defined periodicity to the vertices.


The manual method of meshing one side, copying it to the other, then locking those periodic nodes (lock under Edit Mesh => Repair Mesh), and then patch dependent meshing the remaining surfaces is also possible... But takes a little more skill (more steps and the sequence matters).

I think it would be easier to figure out what wrong octree settings you were using that gave you a bad mesh in the first place.

ale-kc November 15, 2010 09:08

Thank you for your advice.

Yes, first of all I setup periodicity in Mesh Tab => Global Mesh Parameters. But my problem is bad geometry (little bit isn't periodic).

And I think to mesh surface separately then to assign periodic nodes but it's too hard lock those periodic nodes using Edit Mesh => Repair Mesh because I have about 1000 nodes per surface.

That is why I try to find another solution of my task.

PSYMN November 15, 2010 09:47

Start with periodic geometry...
 
Go back and fix your geometry... You can't fake periodicity. The solver will check and if it isn't actually periodic, your Boco will fail anyway and all you meshing effort to generate something "almost periodic" will be for nothing.

PSYMN November 15, 2010 09:49

Or do you mean...
 
Or do you mean that parts of your geometry are periodic and parts are not? And since ICEM CFD is setup to handle "global" periodicity, you would like to use a more local periodicity (aka Match Faces)?

ale-kc November 15, 2010 10:18

Yes exactly! Some parts in my detail have a small shift in comparison to other side.
And I'd like to make periodic faces then make solid mesh.

PSYMN November 15, 2010 14:23

ANSYS Meshing
 
It is still not clear to me what you want to do or why (a sketch would do wonders here)...

But perhaps you should take a look at ANSYS Meshing in WB. This can run off your ICEM CFD (full) or ICEM CFD Tetra key.

ANSYS Meshing has a "Match Faces" option that lets you easily generate bottom up tetra/prism mesh in this way. You set everything up normally, but also right click on "mesh" and insert a "Match Faces". Then you just select which faces should match and it does the rest automatically.

The same end result can be done in ICEM CFD, but is more "interactive" and doesn't have the nice Sizing function, etc. that you get from WB.

Best regards,

Simon


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