FreeCAD OpenFOAM unable to create mesh

A subforum specific to the development of the OpenFoam-based workbenches ( Cfd https://github.com/qingfengxia/Cfd and CfdOF https://github.com/jaheyns/CfdOF )

Moderator: oliveroxtoby

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mkylstra
Posts: 4
Joined: Sat May 23, 2020 1:03 am

FreeCAD OpenFOAM unable to create mesh

Post by mkylstra »

I am new to FreeCAD, and was very exited to try some of the OpenFOAM tutorials. When running the Mesher (regardless whether cfMesh, snappyHexMesh, or gmsh), the operation never completes. The "Report View" shows:

Your choice of mesh element sizes will likely produce a very
large mesh. Do you really want to continue?

(To disable this warning in the future, select `Enable expert mode'
in the option dialog.)

Regardless what parameters I use, I get this same message. Where can I "Enable export mode"? Is there an .opt file? How can I get past this point? Google was no help.

Your help is appreciated.

Installation:
I installed CfdOF, and completed all the CFD installations in the Edit -> Preferences menu of FreeCAD. Yes, I patiently waited for the installation to complete.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
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kkremitzki
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Posts: 2511
Joined: Thu Mar 03, 2016 9:52 pm
Location: Illinois

Re: FreeCAD OpenFOAM unable to create mesh

Post by kkremitzki »

Post moved to CFD section as you may be able to get better help there
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thschrader
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Posts: 3129
Joined: Sat May 20, 2017 12:06 pm
Location: Germany

Re: FreeCAD OpenFOAM unable to create mesh

Post by thschrader »

mkylstra wrote: Sat May 23, 2020 1:20 am ...
Your choice of mesh element sizes will likely produce a very
large mesh. Do you really want to continue?
Welcome.
Interesting report-message, but I never got one even when using mio of cells.
Here is an example from Macer1902 (6 mio cells in 97 minutes):
https://forum.freecadweb.org/viewtopic.php?f=37&t=46505

Can you post your Freecad-file?
You can estimate the number of cells by calculating body-volume/max-cell-size^3
before meshing.
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oliveroxtoby
Posts: 812
Joined: Fri Dec 23, 2016 9:43 am
Location: South Africa

Re: FreeCAD OpenFOAM unable to create mesh

Post by oliveroxtoby »

mkylstra wrote: Sat May 23, 2020 1:20 am I am new to FreeCAD, and was very exited to try some of the OpenFOAM tutorials. When running the Mesher (regardless whether cfMesh, snappyHexMesh, or gmsh), the operation never completes. The "Report View" shows:

Your choice of mesh element sizes will likely produce a very
large mesh. Do you really want to continue?

(To disable this warning in the future, select `Enable expert mode'
in the option dialog.)

Regardless what parameters I use, I get this same message. Where can I "Enable export mode"? Is there an .opt file? How can I get past this point? Google was no help.

Your help is appreciated.

Installation:
I installed CfdOF, and completed all the CFD installations in the Edit -> Preferences menu of FreeCAD. Yes, I patiently waited for the installation to complete.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
I can only assume this is to do with the triangulation process used to generate the STL files for OpenFOAM. I would need to see your model. Can you post your file here?
Please provide all the information requested in this post before reporting problems with CfdOF.
mkylstra
Posts: 4
Joined: Sat May 23, 2020 1:03 am

Re: FreeCAD OpenFOAM unable to create mesh

Post by mkylstra »

Thanks for your fast response! I feel so silly. It turns out, you get this error when you try to "Run Mesher", without creating a Mesh case first. I had some cfMesh installation issues after my first attempt, so I reinstalled cfMesh. When I ran the Mesher again, I encountered the error. In short, if you encounter this error, please make sure you click the "Write mesh case" first. Thanks again for the fast response.
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oliveroxtoby
Posts: 812
Joined: Fri Dec 23, 2016 9:43 am
Location: South Africa

Re: FreeCAD OpenFOAM unable to create mesh

Post by oliveroxtoby »

mkylstra wrote: Sat May 23, 2020 9:08 pm Thanks for your fast response! I feel so silly. It turns out, you get this error when you try to "Run Mesher", without creating a Mesh case first. I had some cfMesh installation issues after my first attempt, so I reinstalled cfMesh. When I ran the Mesher again, I encountered the error. In short, if you encounter this error, please make sure you click the "Write mesh case" first. Thanks again for the fast response.
No worries! It should certainly give a more useful error message...
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