Conformal mesh without commercial software

Hello everyone,

I have a little project and that will help us all here in our forum!
I want to create a multibody mesh with opensource programs like FreeCAD and Salome and later with GMSH.

I found this article:
http://onelab.info/pipermail/gmsh/2015/010110.htm

I used before Star CCM+ and it was no problem for making conformal multibody meshing but I don’t want to use it anymore. With CFMesh+ it’s also possible and I tried it, it works fine! But as I said I want to use opensource programs.

I tried something:
I made a reactionzone (inner pipe) and a pipe which have a bigger diameter at the same point (on XY Plane). Like in this picture:
FreeCAD before boolean operations —> https://i.imgur.com/gNWLMJj.png


As I said I made many conformal mesh in my life and knows it’s better to make a differenz between the reactionzone+sweep and the reactionzone. So the result is only the sweep which is around the inner pipe (reactionzone). After I did a bollean operations —> FreeCAD after boolean oprations: https://i.imgur.com/VQwWLWD.png

Than I exported booth step files and import it into Salome.
Salome before partitioned: https://i.imgur.com/J89FvOM.png

Than I did the partition but is it right with solid? Or maybe shell?
Salome partition: https://i.imgur.com/ffSQDE6.png


After partition it’s looks like so —> Salome after partitioned:
https://i.imgur.com/J89FvOM.png

Here I found one very usefull video:
https://youtu.be/U4qTv7UFFdA

This is my effort from today after using first time both softwares. I am sure that we can fix the case.

In the last Video (YouTube) the man using two cubes and the one cube 1 (the ground) is conected to the bottom auf Cube 1. Than he said that cube 1 the ground is the fix area and from cube 2 the over bottom is the top.. but what subtle fix and top area in my case?


My desired result: a multibody region where I can define two different physics and the boundary layer to the next region not will be merged. The most conformal mesh tutorial make two geometries one, but I want two separate from each other but where the nodes meet.

Thanks a lot and I hope we will solve this case.

Big regards

CFD2D

PS: after it works in Salome, I want to try it in GMSH (after partitioned in Salome). Than write a Pythonskript that make all automatically and all in this forum can use it.

But how I can put it on a cylinder and a hole-cylinder who including the first one like in my picture?

Edit: we solved today the problem 💪🙏

Thank you for sharing, that is very nice. Hopefully we can make it easier and more semless in the future.

Precise Simulation wrote

Thank you for sharing, that is very nice. Hopefully we can make it easier and more semless in the future.

My opinion is better to use one software, which make one thing good.. for example.. FeaTool can make a grid etc. but not conformal multi body mesh, right?
So our workflow will looks like so:
1. FreeCAD for making the CAD geomtry and set constrains (parameter )

2. than do a partition but like in this video: https://youtu.be/pdlUbAUb1GY

Now I have 6 faces, 2 volumes and 1 compound 💪😂!

3. export as brep file and import it in gmsh and meshing there because gmsh-openmpi we can run in a cluster..

4. export the gmsh mesh file and import in FeaTool for solving the equations like point 3 with openmpi

5. for point 1-3 we will now write a python Skript that all working automatically for meshing conformal grid/mesh💪

6. Conect all in simulink and doing shape optimisation like comsol/ansys/starccm+ and that for not so much much money like them😁


Best regards
CFD2D
Best regards