CFD Online URL
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Contraction/Expansion of a Channel Flow

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 11, 2013, 08:53
Default Contraction/Expansion of a Channel Flow
  #1
New Member
 
Danny Moore
Join Date: Jun 2013
Location: Vermont, USA
Posts: 14
Rep Power: 3
Dmoore is on a distinguished road
Send a message via Skype™ to Dmoore
Hello!

I am working to use snappyHexMesh to mesh and simulate a 3-D .stl file of a channel flow contraction in openFOAM v2.2.0 to be run on a 24 core machine using a parallel approach and the simpleFOAM solver. So far I have successfully set up a blockMesh backround mesh, extracted surface features using surfaceFeatureExtract, decomposePar to decompose the case into the proper set of domains. But when I execute:

mpirun -np 24 simpleFoam -parallel > log &

I receive errors saying:

[1] --> FOAM FATAL IO ERROR:
[1] Cannot find patchField entry for contraction_contraction
[1]
[1] file: /home/teamsoh/OpenFOAM/teamsoh-2.2.0/run/sohWind/bigBlock/processor1/0/p.boundaryField from line 26 to line 45.
[1]
[1] From function GeometricField<Type, PatchField, GeoMesh>::GeometricBoundaryField::readField(const DimensionedField<Type, GeoMesh>&, const dictionary&)
[1] in file /home/opencfd/OpenFOAM/OpenFOAM-2.2.0/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 154.
[1]
FOAM parallel run exiting


I have found the offending code line "contraction_contraction". It exists only in the processor files after decomposePar is executed, casefile/processor#/constant/polymesh/boundary (ie it does not exist in the original casefile/constant/polymesh/boundary file). But I have yet to see a problem with the format/syntax/code structure etc...

Is there anyone who might suggest a strategy for resolving this error? Or perhaps a better method for simulating a channel flow (with a contraction and expansion)? Any input is much appreciated! Thank you
Dmoore is offline   Reply With Quote

Old   June 12, 2013, 02:31
Default
  #2
Super Moderator
 
niklas's Avatar
 
Niklas Nordin
Join Date: Mar 2009
Location: Stockholm, Sweden
Posts: 692
Rep Power: 18
niklas will become famous soon enough
does it work for a single run, ie non-parallell run?

thats the first thing to check
niklas is offline   Reply With Quote

Old   June 12, 2013, 12:24
Default
  #3
New Member
 
Danny Moore
Join Date: Jun 2013
Location: Vermont, USA
Posts: 14
Rep Power: 3
Dmoore is on a distinguished road
Send a message via Skype™ to Dmoore
Yes, but very slowly. It is a rather large domain.
Dmoore is offline   Reply With Quote

Old   June 12, 2013, 14:22
Default P file missing from parallel run
  #4
Senior Member
 
JR22's Avatar
 
Jose Rey
Join Date: Oct 2012
Posts: 119
Rep Power: 8
JR22 will become famous soon enough
Check your 0 directories under your processor directories. The decomposePar might not be copying the files (your error is telling you it can't find the "p" file). If this is the case, you can either copy the files using the "cp" linux command or reconstructing (using "reconstructPar" and "reconstructParMesh -constant") and decomposing once more.

Check the post before the last in the thread; I wrote the Allrun file that goes through the cycle to solve the problem:
parallel Grief: BoundaryFields ok in single CPU but NOT in Parallel

Last edited by JR22; June 13, 2013 at 20:01. Reason: adding link to old post
JR22 is offline   Reply With Quote

Old   June 12, 2013, 14:31
Default
  #5
New Member
 
Danny Moore
Join Date: Jun 2013
Location: Vermont, USA
Posts: 14
Rep Power: 3
Dmoore is on a distinguished road
Send a message via Skype™ to Dmoore
Thank you! I will look into that. Is it also possible that paraView is not seeing the .stl surface that I am trying to snap to? I cannot seem to open it independently through paraView. The only way I can see it is to execute surfaceFeatureConvert to move the eMesh file to a .obj (like the tutorials) and then view it.
Dmoore is offline   Reply With Quote

Old   June 13, 2013, 20:00
Default Fixing STLs with mesh repair software
  #6
Senior Member
 
JR22's Avatar
 
Jose Rey
Join Date: Oct 2012
Posts: 119
Rep Power: 8
JR22 will become famous soon enough
If you created your STL on your own, I would go back to your CAD program and play around with the STL export options until you get it to open in paraView. Paraview's STL import is pretty robust, and if your STL has problems it is likely to create problems for you in the near future. If you can't remake the STL, then you can try adjusting it with one of the STL mesh repair programs that are usually used for 3D printing and prototyping. Two come to mind:
  • NetFabb has a free version that works.
  • MeshLab is the most commonly used Open Source Mesh Repair software. It has a lot of options, but if you google it, you will find tutorials that tell you what filters to use to repair STLs
JR22 is offline   Reply With Quote

Reply

Tags
boundary, channel flow, patchfield, snappy hex mesh, wind tunnel

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Channel flow using InterFOAM DanM OpenFOAM Running, Solving & CFD 36 April 23, 2014 08:51
[ICEM] Flow channel meshing problems StefanG ANSYS Meshing & Geometry 19 May 15, 2012 07:44
references for how to maintain a constant flow rate in turbulent channel flow amirrstg Main CFD Forum 0 October 25, 2011 04:17
Stabilizing turbulence equation in channel flow Biga Main CFD Forum 5 March 22, 2005 21:06
Inviscid Drag at subsonic, subcritical Mach # Axel Rohde Main CFD Forum 1 November 19, 2001 13:19


All times are GMT -4. The time now is 00:15.