Test request: OpenFOAM solver for FemWorkbench

[qingfeng.xia]

1. Do you means create a CFD workbench? , that sounds challenging to me, I am not sure how to create Gui/Resource part, maybe I leave the icon still in Fem module (not sure as we did not specify icon path, but icon name),

2. then CMakeLists.txt, Init.py and InitGui.py should be make a pure python module?

You could start the new workbench not in FreeCAD src but in your ./FreeCAD Mod directory in your home directory.With this you need just a few files to start. See https://github.com/berndhahnebach/FreeC ... aster/MyWB for my simple template for a new workbench in Mod directory of your ./FreeCAD folder in your home directory. It has just two simple tools. With this there is no Cmake needed, because no installation is needed.
Later if you would like to go for a PullRequest to integrate it in FreeCAD source you could add the Cmake stuff.

3 . If I need the post-processing and creat-meshing command, can I just import from "_CommandFemMesh.py" or I must copy into new module?

You can use any module and any object from any module in any other module. It just need to be available and of couse you need to import the module.

4. I think I need a SelectionObserver python class.

I have one small just for FEM you could import it. Arch has an own python selection observer class. Assambly2 has one too.

5. To add new command MenuItem/ToolbarItem to workbench, I need to add into Fem/Gui/Workbench.cpp. Is that possible to add into InitGui.py now? Or I should make Cfd/Gui/ cpp files.

Yes you could just add it to InitGui.py See my small template.

There are dozens of modules around which are installed in your user Mod. You could have a look at the code if you need something. One of the best is lattice2. I truelly can recomend installing it.

bernd

Thanks very much, it is a promising tutorial, I will try this weekend and let you know. Thanks Qingfeng

[bernd]

Thanks very much, it is a promising tutorial, I will try this weekend and let you know. Thanks Qingfeng

If there are questions just drop a message. In an own module you are free with naming, code style whatever and since you are the first one you can name it CFD

[makkemal]

I have run a number of tests on this which worked
This is going to be the start of a something new
I also think this will fit into its own workbench.
I just needs a few more things to work from start to finish inside freecad

Great contribution thanks

[johan]

I started playing with the CFD WB and it is a great initiative.

I decided to try and setup the lid driven cavity problem and I seem to have some trouble with the unv mesh that FreeCAD creates. After setting up the case, I tried to write the case input, but ideasUnvToFoam complains about

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For group 1 named wall trying to read 0 patch face indices.

and when I looked at the TestCase.unv file I could see that no patch faces are written to the boundaries.

1 0 0 0 0 0 0 0
wall
2 0 0 0 0 0 0 0
slip
3 0 0 0 0 0 0 0
movingWall

Secondly, is it possible to change the direction of the uniformVelocity BC. I tried playing with the "Direction" input option, but I kept running into "Invalid syntax" errors.

[bernd]

I started playing with the CFD WB and it is a great initiative.

I decided to try and setup the lid driven cavity problem and I seem to have some trouble with the unv mesh that FreeCAD creates. After setting up the case, I tried to write the case input, but ideasUnvToFoam complains about

Code: Select all

For group 1 named wall trying to read 0 patch face indices.

and when I looked at the TestCase.unv file I could see that no patch faces are written to the boundaries.

1 0 0 0 0 0 0 0
wall
2 0 0 0 0 0 0 0
slip
3 0 0 0 0 0 0 0
movingWall

What exact are you missing, Are you missing group data in your unv file?

Secondly, is it possible to change the direction of the uniformVelocity BC. I tried playing with the "Direction" input option, but I kept running into "Invalid syntax" errors.

Do you mean constraint Self weight? AFAIK at the moment it is only implemented in CalculiX input writer. The direction and velocity are hard coded there. It goes in z-direction and the velocity is 9.81 kgM/s^2 . Check https://github.com/FreeCAD/FreeCAD/blob ... cx.py#L749

[johan]

With regards to the unv file, it seems like the mesh.obj for some reason does not store the faces of the boundaries (https://github.com/qingfengxia/Cfd/blob ... fdTools.py), resulting in the zero entries when writing the boundary faces. I need to, however, check that I did not somewhere make a rookie mistake in the setup.

I was actually referring to the "Direction" of the ConstraintFluidBoundary and not the gravitational acceleration (g = 9.81 m/s^2) in the self weight constraint. Coming from a flow background, I thought the direction should be specified instead of derived from a geometric entity by selecting an edge or a face. At the moment the ConstraintFluidBoundary allows one to only select faces (not edges as with force constraints in FEM), because for flow problems BCs should only be applied to faces. It might be useful to have the option to select edges when specifying "Direction".

[bernd]

Ahh than both problems seam related to qingfengs code. You may get in contact with him directly. He writes at the forum rarely.
bernd

[johan]

Thanks, I will contact qingfengs directly about the CFD workbench. I did have some trouble getting netgen to build in fedora and I am hoping there is not something that I missed that is causing the problems with my mesh object.

[johan]

We added a couple of extensions to Qingfeng's CFD WB

https://github.com/jaheyns/FreeCAD.git

and it would it would be great to hear what you think. I have also attached the case set up that reproduce the elbow tutorial from OpenFOAM.

It is now possible to run the solver from the workbench. The view results option is still not working and one has to activate the "CfdAnalysis" (which still shows the FEM WB options) before you could setup the fluid case under "OpenFOAM".

[makkemal]

What needs to be installed .
mine does not do anything further that this

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0.0: Check dependencies...
0.0: case writer is called

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makke@ubuntu:~/FreeCAD_comp$ foamVersion 
OpenFOAM-4.1

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pip install pyfoam
Requirement already satisfied: pyfoam in /usr/local/lib/python2.7/dist-packages
Requirement already satisfied: numpy in /usr/lib/python2.7/dist-packages (from pyfoam)

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OS: Ubuntu 16.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9344 +13 (Git)
Build type: Unknown
Branch: CFD
Hash: 5e9900ee4be99e2339c0cd3a81bf9c5365bfe1e2
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17