Computational Fluid Dynamics (CFD) workbench using OpenFOAM

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

thschrader
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

oliveroxtoby wrote: Thu Jan 18, 2018 3:00 pm Can you confirm that if you right-click in the report view and go to options, everything is checked, then re-run the macro please?
Enabled all options in report view, restart FC, open macro, execute:
(@Kunda1: I will try the newest FC0.17, need time to check the FEM/CFD-Preferences)
after_enabling_all_options_in report_view.JPG
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

Kunda1 wrote: Thu Jan 18, 2018 2:55 pm
thschrader wrote: Thu Jan 18, 2018 10:38 am Version: 0.17.12940 (Git)
Perhaps update to latest HEAD (0.17.13050) and retest?
Did the procederes above with the newest dev-snapshot.
No difference when using
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13042 (Git)
Build type: Release
Branch: master
Hash: 9a215440b8a0140dbc2e8778e66cf63feeac7114
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: German/Germany (de_DE)
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oliveroxtoby
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by oliveroxtoby »

thschrader wrote: Thu Jan 18, 2018 4:38 pm Did the procederes above with the newest dev-snapshot.
No difference when using
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13042 (Git)
Build type: Release
Branch: master
Hash: 9a215440b8a0140dbc2e8778e66cf63feeac7114
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: German/Germany (de_DE)
Hi Thomas

Firstly, thanks for all the testing - much appreciated. This is very strange - no idea why it does not give an issue on my system. Perhaps your observation about the solid is a clue. On other geometries I have found the boolean shape splitting operations to be more robust than the 'Cut' operation, so I have modified the macros to use the boolean XOR instead of Cut. If you are willing could you check if this fixes the problem on your system?
Please provide all the information requested in this post before reporting problems with CfdOF.
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

oliveroxtoby wrote: Fri Jan 19, 2018 7:08 am ... so I have modified the macros to use the boolean XOR instead of Cut.
:) :) :) Cheers!
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

@Oliver
I completele deleted FC0.17 (including the config-files) from my pc
and did a new installation. Now I get ONE body when importing the step.
The same happens with the original file from grabcad. I have absolutely no
idea what the reason could be... :o
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by Kunda1 »

Alone you go faster. Together we go farther
Please mark thread [Solved]
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

Kunda1 wrote: Fri Jan 19, 2018 3:54 pm Splash screen anyone?
With a transient simulation (calculation-time!) instead of a steady state we could produce
an animated splashsreen.
But:
The falcon was not designed with FC. The model was taken from grabcad:
https://grabcad.com/library/millennium- ... -version-1
I dont know if this would be correct...
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by thschrader »

Hello Oliver,
I have a general question about cfd-simulations.
Is it always necessary to switch on the turbulence option?
For instance, when I scale up the falcon to its "original" dimension (length approx 34 m)
and use a speed of 300 km/h (when Han Solo approaches the landing zone :) ), you get
a Re-number of approx 1,4E8. The gravitationally-forces of the fluid are dominating and
I would skip the turbulence. Is that right?
How do you estimate the k-omega-values? With a turbulence calculator? Which one?
regards Thomas
http://ichrome.com/blogs/archives/342
https://www.cfd-online.com/Tools/turbulence.php
https://www.learncax.com/knowledge-base ... t-boundary
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by oliveroxtoby »

thschrader wrote: Sat Jan 20, 2018 10:13 am Hello Oliver,
I have a general question about cfd-simulations.
Is it always necessary to switch on the turbulence option?
For instance, when I scale up the falcon to its "original" dimension (length approx 34 m)
and use a speed of 300 km/h (when Han Solo approaches the landing zone :) ), you get
a Re-number of approx 1,4E8. The gravitationally-forces of the fluid are dominating and
I would skip the turbulence. Is that right?
Generally only for laminar flow where Re < O(1e3) is it justified to ignore the turbulence.
thschrader wrote: Sat Jan 20, 2018 10:13 am How do you estimate the k-omega-values? With a turbulence calculator? Which one?
regards Thomas
http://ichrome.com/blogs/archives/342
https://www.cfd-online.com/Tools/turbulence.php
https://www.learncax.com/knowledge-base ... t-boundary
There are some guidelines for the far field values in https://turbmodels.larc.nasa.gov/sst.html
Please provide all the information requested in this post before reporting problems with CfdOF.
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Re: Computational Fluid Dynamics (CFD) workbench using OpenFOAM

Post by bernd »

bernd wrote: Mon Jan 15, 2018 4:53 pm @thomas, FYI
some time ago we had a problem with to much entries in a fixed contraint. Werner fixed the problem and we could have more than 3000 faces as reference shapes. I added them by python.
here some code to add all faces of a shape as reference shapes to an FEM object: https://forum.freecadweb.org/viewtopic. ... 10#p211310
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