CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[Other] meshing suggestions

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 30, 2012, 08:10
Default meshing suggestions
  #1
Member
 
Join Date: Feb 2012
Posts: 57
Rep Power: 14
matt.mech.eng is on a distinguished road
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!!
matt.mech.eng is offline   Reply With Quote

Old   July 30, 2012, 11:07
Default
  #2
New Member
 
James Simpson
Join Date: Jun 2012
Posts: 10
Rep Power: 14
jasimpson89 is on a distinguished road
can't see any screen shot ??
jasimpson89 is offline   Reply With Quote

Old   July 30, 2012, 19:44
Default
  #3
Member
 
Join Date: Feb 2012
Posts: 57
Rep Power: 14
matt.mech.eng is on a distinguished road
sorry about that..
Attached Images
File Type: jpg parabolicProfile.jpg (9.7 KB, 44 views)
File Type: jpg parabolicProfileVertices.jpg (11.2 KB, 34 views)
matt.mech.eng is offline   Reply With Quote

Old   July 31, 2012, 04:26
Default
  #4
New Member
 
James Simpson
Join Date: Jun 2012
Posts: 10
Rep Power: 14
jasimpson89 is on a distinguished road
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
jasimpson89 is offline   Reply With Quote

Old   August 1, 2012, 07:08
Default
  #5
Member
 
Join Date: Feb 2012
Posts: 57
Rep Power: 14
matt.mech.eng is on a distinguished road
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..
matt.mech.eng is offline   Reply With Quote

Old   August 1, 2012, 08:13
Default
  #6
Disabled
 
Join Date: Mar 2011
Posts: 174
Rep Power: 15
anon_a is on a distinguished road
Not a meshing expert here, but what about something similar to the circle mesh?

Check here to see how the circle is done.
http://www.cfd-online.com/Forums/ope...tml#post179978
anon_a is offline   Reply With Quote

Old   August 1, 2012, 08:23
Default
  #7
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 620
Blog Entries: 6
Rep Power: 24
elvis will become famous soon enough
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)
elvis is offline   Reply With Quote

Old   August 1, 2012, 09:42
Default
  #8
Disabled
 
Join Date: Mar 2011
Posts: 174
Rep Power: 15
anon_a is on a distinguished road
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.
anon_a is offline   Reply With Quote

Old   August 1, 2012, 10:11
Default
  #9
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 620
Blog Entries: 6
Rep Power: 24
elvis will become famous soon enough
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
elvis is offline   Reply With Quote

Old   August 1, 2012, 10:16
Default
  #10
Disabled
 
Join Date: Mar 2011
Posts: 174
Rep Power: 15
anon_a is on a distinguished road
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.
anon_a is offline   Reply With Quote

Old   August 1, 2012, 19:39
Default
  #11
Member
 
Join Date: Feb 2012
Posts: 57
Rep Power: 14
matt.mech.eng is on a distinguished road
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!
matt.mech.eng is offline   Reply With Quote

Old   August 1, 2012, 20:39
Default
  #12
Member
 
Join Date: Feb 2012
Posts: 57
Rep Power: 14
matt.mech.eng is on a distinguished road
can pythonFlu/hybridFlu be used with OF2.1.1 and salome 6.4?
matt.mech.eng is offline   Reply With Quote

Old   August 2, 2012, 02:23
Default
  #13
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 620
Blog Entries: 6
Rep Power: 24
elvis will become famous soon enough
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.
elvis is offline   Reply With Quote

Old   August 2, 2012, 02:30
Default
  #14
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 620
Blog Entries: 6
Rep Power: 24
elvis will become famous soon enough
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.
elvis is offline   Reply With Quote

Reply

Tags
2d mesh, hex mesh, hexahedral, quadrangle mesh, salome

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[ANSYS Meshing] Cooper Method Meshing RTN3000 ANSYS Meshing & Geometry 1 March 1, 2015 23:59
[ANSYS Meshing] Meshing cuboidal room with openings nickdaish ANSYS Meshing & Geometry 6 February 21, 2015 11:17
[ICEM] Flow channel meshing problems StefanG ANSYS Meshing & Geometry 19 May 15, 2012 06:44
[ANSYS Meshing] Meshing strategy for External Flows Hybrid ANSYS Meshing & Geometry 0 January 24, 2012 14:27
Best Meshing scheme for Cylinder Nutrex Main CFD Forum 4 July 29, 2008 11:03


All times are GMT -4. The time now is 01:09.