FEM vs CFD vs CFDOF

[RatonLaveur]

Hello to all,

I have had some decent experience a couple of years ago running simulations using CfdOF, for that I thank you. I'm about to go back to CFD using FreeCAD but the ecosystem seems to have a changed a bit. I see that the original CFD workbench is actively maintained, and I see that CfdOF as wel, I see also many CFD related functions in the FEM workbench.

As such I was wondering:
- Can I run CFD simulations directly in the FEM workbench?
- Should I move towards CFD or CfdOF ?

Thank you for your work! (and, in advance, for your answer)

[thschrader]

With the FEM-wb you can use the elmer-solver for CFD.
https://forum.freecadweb.org/viewtopic. ... &start=220

The cfdof-wb uses openfoam (bluecfd-core for windows)
https://forum.freecadweb.org/viewtopic. ... &start=110

elmer.JPG (46.77 KiB) Viewed 2314 times

openfoam.JPG (98.52 KiB) Viewed 2314 times

[RatonLaveur]

Hello thschrader, thanks for the update.

I'm really interested in trying out the Elmer solver for the following (admittedly arbitrary) reasons:
- I like that its fully integrated in the FEM workbench (seems neater)
- The selection of boundaries is made clearer with the glyphs (including the direction of flow/pressure constraints)

I am aware that it has some limitations at the moment (no plot of residuals).

I prepared the attached file

Test_Elmer_CFD.FCStd

(210.28 KiB) Downloaded 63 times

and tried to run it, but it seems it does not find the Elmer binaries. I can't manually find them either in the FreeCAD directory. I therefore assume that I am missing a key piece of the puzzle (similar to BlueCFDcore needed for CfdOF).

Looking for Elmer in the forums, there are many conversations but I could not find a clear tutorial for installation and running basic sims. Perhaps I have not been looking in the right place. Is there anyway you could point me to some resources on installing and running Elmer based CFD models in FC?

EDIT: further looking led me to bernd's post about installing Elmer https://forum.freecadweb.org/viewtopic. ... er#p366419

Thanks in advance.

[qingfeng.xia]

CFD almost hints finite volume method to solve fluid problem, there are more models for Finite volume methods, that is why CFD and FEM are seperated in FreeCAD, as other simulation software.