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[ICEM] No pyramids between tetra and Quad

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Old   February 3, 2011, 02:38
Default No pyramids between tetra and Quad
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jeevan kumar
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Hello All,

i am working on the Tetra meshing on a aircraft with propeller considering it has a disc. i have created the surface mesh and then extruded the tri mesh on the disc to create prisms inside the disc. Then taking only the shell mesh i have generated the Tetra for the external domain. But since there is quad mesh on the disc, ICEM has to generate Pyramid between this quad and the Tetra. But i dont know why it is spliting this pyramid cell into tetra?
Please look at the images attached.


i am used ICEM12.1, with Volume Method «*Delaunay*» Options: «*TGlib*» with «*AF*».

Please can anyone tell me what it is not creating the pyramid cell?

Thanks in advence
Jeevan
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Old   February 3, 2011, 13:14
Default Are you sure? It works for me...
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Simon Pereira
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I replicated your setup and had no issues. I noticed a problem if I left the extruded volume mesh in for the delaunay operation, but not if I deleted those volume elements and started with just surface mesh.

Here you can see that I have a pyramid for every Quad in my extruded disk.

I don't know of any setting that would convert these to tetras during delaunay, but there are options that convert pyramids to tetras after the fact. And there are also options that could have converted the quads to triangles before you ran delaunay.

Maybe take another look at your process and make sure you don't have pyramids at the end? How sure are you that you had quads before running delaunay. Sorry, just trying to cover the bases since this should work no problem...

Pyramids_On_Extruded_Disk.jpg
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Old   February 3, 2011, 13:22
Default Version 12.1 and my test case.
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Simon Pereira
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Oh yea, I also tested in 12.1...
Pyramids_On_Extruded_Disk_121.jpg


And here is the test case... I have already removed all the volume elements... Just load and run delaunay. See if this works properly for you.
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Old   February 4, 2011, 02:46
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Thank you Simon for the reply,

I also did such kind of a test to see if it is generating the pyramids, Yes it did generate the pyramid for simple case and with small mesh size. I used the same process.

But i am not able understand why it is not generating for my case which has much big mesh size. I have quad cells on the disc, since i have extrded the tri cells and it will generate the quad elements on the sides of the disc.

i need this prisms inside the disc and i dont know what is the problem.

Thank you
jeevan
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Old   February 4, 2011, 10:52
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It shouldn't be any different for a larger model. So I can scale up my test, how large is your model (number of tri's and number of quads)?
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Old   February 9, 2011, 05:18
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Thank you simon.

sorry i cannot send the surface mesh.

my mesh has 523457 tri's and 189 quad cells

regards
jeevan
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