[HorstvanGrass]

Hi,
I have a multiRegion case with 3 different region (region0, Fluid and region 1) as simplified in the attached image. I'm using snappyhexmesh for snapping a STL geometry. For my mesh study the region 0 and region 1 are randomly switching which is pretty anoying to adapt the boundary condition before each run.


I would like to precisely rename the undefined regions in outer cell region and inner one before splitting with splitMeshRegion -cellZones . I tried with locationsInMesh command but it conflicts resulting in new nonsense domains.



Thx in advance

[Yann]

Hi,


I usually use locationsInMesh to define cellZones in multi region cases. How do you define it and what issues are you having with it?


Yann

[HorstvanGrass]

After some try and error, I found that a refinement definition cause problems when using locationsInMesh.
I removed the highlighted part and now its not conflicting.



refinementSurfaces
{
Fluid
{

level (0 0);
faceZone Fluid;
cellZone Fluid;
cellZoneInside inside;
}

[Yann]

OK I understand. In your code, you are defining a cellZone in refinementSurfaces.

refinementSurfaces
{
    Fluid
    {
        level (0 0);
        faceZone Fluid;
        cellZone Fluid;
        cellZoneInside inside;
    }
}

But the locationsInMesh function is also used to define a cellZone:

locationsInMesh
(
    (( 0.005 0.005  0.005) Fluid)
    (( 0.05  0.005  0.005) Solid1)
    ((-0.05  0.005  0.005) Solid2)
);

I guess you cannot use both mechanisms at the same time. You have to choose if you want to define your cellZones in refinementSurfaces or with locationsInMesh.

Yann


PS: just a clarification for people reading this thread: locationsInMesh is only available in the ESI-OpenCFD branch (openfoam.com). In the foundation branch (openfoam.org) you have to define your cellZones in refinementSurfaces.

[HorstvanGrass]

Thanks for the explanation. Helped me a lot!

[HorstvanGrass]

Hey Yann,
locationsInMesh is however creating a hole in my Mesh, as you can see in the center of the image for my coarse mesh. This does not occur when defining with refinementSurfaces. Is there a way to fix the hole or to define explicitly the unnamed region with therefinementSurfaces as with locationsInMesh?


Thx in advance


hole.png

[Yann]

I'm not aware of a way to fix it except by playing around with the refinement levels (this is very coarse!) and maybe some snapping parameters.


Maybe someone else will have an idea?


Yann

[HorstvanGrass]

I managed it to solve the naming of the region by roughly attributing cellzone with toposet for region 1 and 2 naming them solid 1 and 2. Then execute sHM which substract the dupllcated cells in the cellzone and adding them to Fluid. Then there three distinct named region.