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benjy78 March 3, 2011 09:35

mesh Mixing elbow 3-D
Hello everybody,
I'm a new CFD user, I hope this is the right place.

I'm trying to do the first exercise of the Fluent's user's guide, not in 2D but in 3D, but I have some problem with the mesh in Gambit.

I built the geometry as the union between two cylinders and a portion of a torus. But I can't mesh the volume of the torus........ why? What can I do?

Thanks for helps

P.s. where I can find some simple exercise to enlarge my knowledge (a part the user's guide of Gambit and fluent)?

alastormoody11 March 3, 2011 23:54

Check whether you have deleted the split surface created from the intersection.

That is there should be no internal surfaces inside your CV.

As guidance regarding tutorials the help for FLUENT is available online though for an older version but you might give it a shot.

Ramon Quiñonez October 25, 2017 22:20

Problem with mixing elbow
Dear All.

I'm new into CFD . I am trying to mesh the geometry of the first FLUENT tutorial in GAMBIT, however I just cant do it, I have tried to separate both volumes (the 90° elbow with large inlet and outlet, and the small inlet), and then I can only mesh the small inlet.

I have even separated the mixing elbow into four volumes ( 3 half cylinders and the 90° elbow) and tried to mesh them, however I cant mesh the elbow.

Could you please help me?:)

Many thanks

-mAx- October 26, 2017 00:58

can you post a picture?

Ramon Quiñonez October 26, 2017 12:48

mixing elbow (SAT)
1 Attachment(s)
I attach the picture with the geometry

Many Thanks :)

-mAx- October 27, 2017 00:44

how did you managed to split the volume?
In your case the difference will be that you will handle virtual geometry because you imported a *.sat file.
In the tutorials they are working with real geometry which is more easy.

Ramon Quiñonez October 30, 2017 23:59

meshing the mixing elbow
I did the geometry by using SOLID WORKS, I have exported it either IGES or SAT, however I cant mesh the geometry, I presume the problem is in the junction of the small inlet with the elbow.

-mAx- October 31, 2017 01:51

I asked how did you manage to try to split the geometry?

in virtual geometry, you need to split first your symetry plane with the 2 vertices. It will generate a line which splits the surface.
Then create a surface by selecting this line and also the semi circle.
Finally split the volume with this surface.
That's it, you have now 2 separated volumes.

Ramon Quiñonez October 31, 2017 02:15

1 Attachment(s)
yes, I did the same procedure. At that point I am able only to mesh the small inlet. How would you mesh the big volume.

Many thanks for your time. :)

-mAx- October 31, 2017 02:23

you can mesh it directly with tetra (unstructured).
But I would split you volume twice again. Use both semi-circles prior to and after the small inlet.
Then mesh both big tubes with hexa, and the remaining domain with tetra (hexcore).
You may also use a size function to refine automatically untill your small inlet

Ramon Quiñonez October 31, 2017 02:28

Thanks, I forgot to mention that I would like to mesh by using hexahedral elements or hex/Wedge.

-mAx- October 31, 2017 02:32

ok, then check this tutorial:

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