CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM (https://www.cfd-online.com/Forums/openfoam/)
-   -   mergeMeshes hex + tet (https://www.cfd-online.com/Forums/openfoam/89785-mergemeshes-hex-tet.html)

flowris June 22, 2011 09:10
mergeMeshes hex + tet
 
1 Attachment(s)
Hello,

I want to do mergeMeshes on a hex and a tet mesh, see picture. Is this possible? When I run
mergeMeshes . grid1 .grid2
I get
Code:
Master:      "." "grid1"  region region0
mesh to add: "." "grid2"  region region0

Create Times
Reading master mesh for time = 0
Create mesh

--> FOAM Warning :
    From function directTopoChange::addMesh(const polyMesh&, const labelList&,const labelList&, const labelList&,const labelList&)
    in file directTopoChange/directTopoChange/directTopoChange.C at line 2281
Segmentation fault

stevenvanharen June 22, 2011 09:24
You need to have a conformal interface as far as I know.

This is not the case for you. I don't know how you made the mesh, but maybe you can retry with a conformal interface. I think it will work than.

Logan Page June 22, 2011 15:16
You can create nice hybrid structured / unstructured meshes with gmsh (tho it can take a while to setup for more complex geometries). This also imports into OpenFOAM quite nicely.

Arnoldinho June 23, 2011 02:45
Quote:
I want to do mergeMeshes on a hex and a tet mesh, see picture. Is this possible?
I don't know the source of your error message, but it is generally possible to merge tet + hex meshes and use them in OF, see attached picture. I made this using blockMesh, salome, engrid, mergeMeshes and stitchMesh.
Generally I would not recommend it, as you can get a lot of trouble using tet meshes (at least when using the interFoam solver). You could try snappyHexMesh instead.

http://img830.imageshack.us/img830/8...nedmesh.th.png

Arne

kdneroorkar June 23, 2011 09:14
I know you can have non-conformal interfaces using ggi patches, but I am not sure if it is alright to have one side hex and another side tet. Does anyone know about this?

deepsterblue June 23, 2011 10:10
GGI doesn't really care about cell-topology on either side. The only limitation is that patch faces be convex, because of a limitation in the intersection algorithms.

flowris June 23, 2011 10:53
A little explanation
 
1 Attachment(s)
Thanks for the many replies.

A little explanation: I made a tet mesh around a foil inside a circle with gmsh. Now I want to add layers on the foil surface. As far as I know, this cannot be done in gmsh, because the foil is an extrude spline profile.

If I use
refineWallLayer -overwrite airfoil 0.3
I get a bad layer with skew cells, see picture.

So any suggestions on how to ad these layers?

Arnoldinho June 23, 2011 11:03
Quote:
A little explanation: I made a tet mesh around a foil inside a circle with gmsh. Now I want to add layers on the foil surface
If you just want to add layers, you might become happy with engrid! On simple structures, I achieved good results with this tool (which is not part of OF!). But it only seems to work for 3D cases - I don't know what your case is.

RefineWallLayers might not be a good choice in your case, as it just splits your surrounding cells.


All times are GMT -4. The time now is 20:34.