CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

BlockMesh versus gmsh2ToFoam

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

LinkBack Thread Tools Search this Thread Display Modes
Old   March 6, 2008, 09:50
Default Hi guys, I am relatively ne
New Member
Brett Tully
Join Date: Mar 2009
Posts: 2
Rep Power: 0
bretttully is on a distinguished road
Hi guys,

I am relatively new to OpenFOAM and am trying to assess if it is a suitable tool to use for my DPhil.

I have started by trying to design a simple case to test features that I will need to use.
I have a 1/4 circle extruded to make a "wedge" cylinder. The flat surfaces are symmetry conditions, and the circular face is a wall (essentially forming an pipe), the ends are inlet (fixed velocity) and outlet (fixed pressure).

I can run this with a blockMesh generated mesh with no problems, however, it will be important for me eventually to be able to use unstructured tet meshes. For this, I have written a *.geo file and fed it to gmsh2ToFoam and as far as I can tell the generated mesh is decent (viewed in paraFoam, and run checkMesh). Yet, if I pass the same control/initial conditions from the blockMesh case to this one, the first few iterations _converge_ but it eventually blows up. Looking at the results from the first few iterations with paraFoam shows that these solutions are not at all correct.

Can anyone suggest where I can look to see what is causing the trouble. It is important to be able to use unstructured grids, as my project will require some very complex meshes.

bretttully is offline   Reply With Quote

Old   March 6, 2008, 10:36
Default Hi Brett, I've also just star
New Member
Christian Wesemeyer
Join Date: Mar 2009
Posts: 19
Rep Power: 16
wese is on a distinguished road
Hi Brett,
I've also just started using openFOAM.
So I also tried to simulate the flow through a circular pipe.
First I've tried icoFoam, but my results also were divergent.
So I've switched to simpleFoam for the steady state solution but even now I received strange results.
After a while I figured out, that the "double used" points (as described on p. 148 of the users manual) in the middle of the tube were the problem (but untill now I have no idea why).
An image of the calculated velocity profile is in the attached case (t1_u.jpg).
After I've put then on one of the sides everything worked fine (see images the attached case):

wese is offline   Reply With Quote


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
[Gmsh] GmshToFoam or gmsh2ToFoam amp gmsh sudden disappear zhoubinwx OpenFOAM Meshing & Mesh Conversion 20 August 7, 2009 19:07
[Gmsh] Gmsh2toFoam sega OpenFOAM Meshing & Mesh Conversion 16 April 27, 2009 09:23
Dissimilarity in compiling new BC in 32bit OpenSuSE 103 versus 64bit CentOS 50 versus 64bit SLED 100 sponiar OpenFOAM Running, Solving & CFD 3 February 26, 2008 07:31
[Gmsh] Gmsh2ToFoam bsegmentation faultb error in OF13 Release ed_teller OpenFOAM Meshing & Mesh Conversion 3 September 10, 2007 17:53
AMG versus ICCG msrinath80 OpenFOAM Running, Solving & CFD 2 November 7, 2006 16:15

All times are GMT -4. The time now is 03:16.