[twinturbotom]

Hi all!
I'm missing a few settings and/or a fundamental understanding of snappyHexMesh. I've used numerous resources (including this forum) yet I continue to fall short of my simple goal to mesh the inside of two volumes in the attached case.

I'm able to mesh the interior of one (1) volume OR the other, never both at the same time. sHM seems to only mesh the volume that contains the "locationInMesh" point.

If I move the "locationInMesh" point outside of my two volumes I am able to boolean the two (2) volumes from the surrounding blockMesh; however I need the opposite.

I've tried numerous region definitions for faceZone, cellZone, allowFreeStandingZoneFaces, and various other options from the numerous multiple region tutorials I could find. I have yet to mesh the interior of block1 and the adjacent block2.

Could someone explain what I'm missing here?
Do I need individual stl files (as packaged here) to mesh the interior of both volumes or can regions/zones be used with a single stl? I have successfully used regions in other stl files to control boundaries, never entire volumes like this.

[twinturbotom]

The attached files work!
All I needed to do was "Include Zones" in the ParaView properties.

Hopefully this can help someone else in meshing multiple volumes with snappyHexMesh.

[jhoepken]

Without having had a look at your specific problem, I assume that you would like to mesh something similar to the inside of two spheres, that are not connected to each other. Right?

As far as I know, this is not possible with a single snappyHexMesh run. You could mesh the one and then the other sphere, in two separate cases. When this is done, use mergeMesh to merge both meshes into one.

[mismichael]

Hi,

I tried to open the file. It is damaged or I am doing something wrong with gunzip.

[vineet_bhola]

Hi Guys,
It is indeed possible to mesh two or more volumes in a single run of snappyhexmesh. It works well if the surfaces do not cut each other. What you have to do is define the volumes as different cellzones surrounded entirely by closed facezones(boundary to the same volume as cellzone)
(Inside Snappyhexmesh):
refinementSurfaces
{
abgas
{
// Surface-wise min and max refinement level
level (2 2);
faceZone abgas;
cellZone abgas;
zoneInside true;
}
solid
{
// Surface-wise min and max refinement level
level (2 2);
faceZone solid;
cellZone solid;
zoneInside true;
}
wasser
{
// Surface-wise min and max refinement level
level (2 2);
faceZone wasser;
cellZone wasser;
zoneInside true;
}
}

and later run commands to extract only these cellzones from the complete block.

setSet -batch batch.setSet
subsetMesh -overwrite isolation

This is required because if there are more than one stl surfaces, snappy cuts the volume but does not discard the rest of the volume.

You also need to add a .setSet file with the following content to define "isolation" volume. (P.S. isolation is just a name..not a keyword)

cellSet isolation new zoneToCell solid
cellSet isolation add zoneToCell wasser
cellSet isolation add zoneToCell abgas
cellSet isolation subset

check out the original discussion here:
http://www.cfd-online.com/Forums/ope...tml#post341623