|September 26, 2013, 12:53||
empty patch as farfield condition
Join Date: Sep 2009
Location: Tehran, Iran
Blog Entries: 1Rep Power: 14
please look at the attached file, this file solves a flow over plate by simpleFoam solver in OF-2.2.0, instead of farfield condition, it uses empty BC. I expected it crashes, but it works fine, so whats farfield BC for p,U, and so on? how they can be calculated when we assign it an empty patch?
|September 26, 2013, 15:58||
Niels Gjoel Jacobsen
Join Date: Mar 2009
Location: Rotterdam, The Netherlands
Posts: 1,593Rep Power: 24
That is very strange. I quickly tried the case on a couple of versions of OpenFoam, and the report is as follows:
- OF2.2.1: The attached simulation runs.
- OF2.2.0: The attached simulation runs.
- OF2.1.0: The attached simulation runs.
- OF1.7.1: The attached simulation fails.
- OF1.6-ext: The attached simulation fails.
Looking at the data, where is actually a non-zero velocity normal to the farfield boundary, so how does an empty boundary condition behave?
This must be a bug in the mesh check prior during runTime. It is on the other hand interesting that only in OF2.1.0 and OF2.2.* does checkMesh complain over the mismatch between number of empty faces and the number of cells. This is not part of the response in neither OF1.7.1 nor OF1.6-ext.
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|April 5, 2014, 13:06||
Join Date: Jan 2011
Posts: 25Rep Power: 6
Have you solved this problem? I faced the problem of how to set far field boundary as well.
Last edited by wyldckat; April 5, 2014 at 16:15. Reason: fixed broken quote
|April 5, 2014, 16:47||
Join Date: Mar 2009
Location: Lisbon, Portugal
Blog Entries: 34Rep Power: 84
Greetings to all!
Thanks to the OpenFOAM-combo repo I created sometime ago ( https://github.com/wyldckat/OpenFOAM-combo/ ), I managed to see what happened in this case.
As of OpenFOAM 2.0.0, they decided to comment out this check, which was made only when the respective debug flag was active. In the latest code at 2.3.x, have a look into the method "updateCoeffs()": https://github.com/OpenFOAM/OpenFOAM...chField.C#L139 - it has this comment there:
|empty patch, farfield|
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