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Old   July 30, 2012, 08:10
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Hi all,

I wonder if anyone has any suggestions on how to generate a 2d mesh of quadrangles for the attached screenshot?

I want to generate a 2d mesh and extrude the profile along z-axis. I have been working for months trying to produce this mesh but have not succeeded in producing a mesh of high enough quality!

Any help would be greatly appreciated!!
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Old   July 30, 2012, 11:07
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James Simpson
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can't see any screen shot ??
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Old   July 30, 2012, 19:44
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sorry about that..
Attached Images
File Type: jpg parabolicProfile.jpg (9.7 KB, 41 views)
File Type: jpg parabolicProfileVertices.jpg (11.2 KB, 33 views)
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Old   July 31, 2012, 04:26
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Maybe try having a look at page 136 and 137 in the user guide. I haven't ever tried meshing an arc but this is where I might start. To then make it 2d look at collapsing some of the mesh points on top of each other (not entirely sure if that would work as I have never generated a 2d geometry) this is explained further on the blockMesh section
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Old   August 1, 2012, 07:08
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I want to generate a 3d mesh, but I have started with a 2d profile which would then be extruded. It is very easy to generate a mesh in this way using Salome.

The real problem is to break the geometry up in such a way as to minimize skewness and non-orthogonal cell faces..
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Old   August 1, 2012, 08:13
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Not a meshing expert here, but what about something similar to the circle mesh?

Check here to see how the circle is done.
Help could anyone post a simple cylinder mesh
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Old   August 1, 2012, 08:23
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Hi,

what about using http://pythonflu.wikidot.com/hybridflu it is the direct way to import mesh from Salome to OF and it does support more mesh types (better to use compared to ideasUnvToFoam)
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Old   August 1, 2012, 09:42
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Hey Elvis,

what are the advantages of hybridflu compared to ideasUnvToFoam?
I am looking for this information in the site you provided but have not found it yet.
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Old   August 1, 2012, 10:11
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Hi anon_a,

if you search you will find people complain that the conversion of their mesh did fail via ideasUnvToFoam quite often, because the ideasUnvToFoam converter does not convert all types of mesh that you can produce with salome.

http://www.openfoamworkshop.org/6th_...ord_slides.pdf
=> take a look at Slide 18 "Meshing" to understand the benefit I want to point at
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Old   August 1, 2012, 10:16
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Very interesting, thanks!
By the way, do you also have any pointers about how to produce polyhedral elements in SALOME?
So far I have been experimenting with polyDualMesh only.
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Old   August 1, 2012, 19:39
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Hi all,

anon_a- I have looked at breaking the geometry up in this way the problem is that I am using bubbleFoam (with modified k-eps model) and I need to have alpha initialised so that alpha equals 1 (ie 100% gas phase) at above height of 0.8m and 0 below this line.
I need to have a region of good refinement around the interface for stability.. and because of this constraint it makes using this method a bit trickier as the mesh tends to become more skewed which also seems to have a big effect on stabilty.

elvis- I have had a look at the link you provided bubbleFoam is not included. In terms of salome and polyhedral cells do you have any pointers? Could you please also specify exactly which cell types ideasUnvToFoam can handle?

Thanks for the help!
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Old   August 1, 2012, 20:39
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can pythonFlu/hybridFlu be used with OF2.1.1 and salome 6.4?
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Old   August 2, 2012, 02:23
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Hi anon_a,

I am absolutly no expert with Salome. I saw an interesseting Post from Tobias Holzmann
pointing http://www.salome-platform.org/user-...edf-exercise-1 to this exercise that I want to go through when I have enough time.

http://www.salome-platform.org/user-section => visit the TUI section and the Tutorials section should give a good impression.

Quote:
salome and polyhedral cells
http://www.salome-platform.org/forum..._938#983021615
Support of polygonal/polyhedral mesh elements and quadratic meshes both in SMESH and VISU; =>
http://www.salome-platform.org/forum..._572#381680501

Last edited by elvis; August 2, 2012 at 03:04.
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Old   August 2, 2012, 02:30
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Hi,

visit the pythonflu help forum http://sourceforge.net/projects/pyth.../forum/1364822 and ask

Quote:
can pythonFlu/hybridFlu be used with OF2.1.1 and salome 6.4?
I am quite sure that it does, if you compile from the sources
(I installed Pythonflu from sources for OF1.6-extend on a aptosid(=debian-based) distribution), so I can not confirm for the OF release you ask.
But Salome should not be the showstopper.

http://pythonflu.wikidot.com/install-sources is not the nicest install manual, if it helps I could post a "nice" install manual (i am biased) for a debian-based distribution

Last edited by elvis; August 2, 2012 at 02:57.
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2d mesh, hex mesh, hexahedral, quadrangle mesh, salome

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