[mamaly60]

Hello

What is the Best mesh generation software for OpenFOAM?

cheers

[mkraposhin]

CalculiX GraphiX, www.calculix.de
SALOME, www.salome-platform.com (or .org?)

[gdbaldw]

For Calculix, you can first model a surface in Blender and then import that surface into Calculix to be extruded. I posted the import script and brief tutorials in a few other threads. Blender is at www.blender.org .

Doug

[msrinath80]

I vote for blockMesh. It may be slightly harder to learn but I find it fun to use. It has all the basic elements you need to create any kind of mesh. You just need a lot of patience. If that does not sound too convincing, try gmsh. It features a GUI and is somewhat easier to use.

[nishant_hull]

I do agree with madhavan.

[philippose]

My vote goes without any second thoughts to the one and only.... Netgen v4.5 :-)!

The software seriously rocks when it comes to mesh generation! I have been using it for over a year now, and always keep it up to date from CVS....

So far... the only complaint I have is that it does not do a good job when there are long narrow gaps (for example concentric cylinders with gaps which are very small compared to the rest of the geometry).

Also... it can only create pure tetrahedral meshes in 3D (though, for my applications... this does not seem to be so much of a limitation)

As for importing into OpenFOAM... flawless.... Mesh Quality... very very acceptable.... Complexity.... hardly complex :-)..... Type of geometries it can handle... yet to find one which it cannot handle :-)!

It can directly import STEP and IGES files (if compiled with OpenCascade support)... and I dont need to do anything special when exporting out of Pro/E.

And on a purely personal note.... I have tried Gmsh and Tetgen... but found netgen to be much more user friendly... and the GUI easier to work with.

Philippose

[mighelone]

If I well understood none of these software is a multi-grid hexahedral mesh generator!?

Does exist a free (open source is better) hexahedral mesh generator, with the features of gridgen?

Michele

[gdbaldw]

I too needed hex, not tet. blockMesh does hex, but is difficult for anything but simple geometry. I assure you that Blender is a very capable tool for generating a surface mesh made of quads, and that Calculix can extrude this surface using the Python script I posted in another thread.

Furthermore, I have a technique now for generating "manifolds" from the Blender surface mesh, and using Calculix to create "columns" of hex between each manifold. To generate manifolds I first use a seperate Python script to project normals from the quad surface and make any manual adjustments needed, then export to Calculix. Exports from Calculix to OpenFOAM are without error.

If you'd like to learn this technique, I'd be happy to share my experience with you through this forum, so that others may also benefit. A formal tutorial is really needed, but for now some of my prior postings may be useful as an introduction to this technique.

Doug

[hsieh]

Hi, Philippose,

Could you please post the link to download netgen 4.5? Thanks!

Pei

[hsieh]

Hi, Doug,

Using blender + calculiX is an interesting concept. What if the 3D shape is irregular (that is cannot simply uses extrusion)?

pei

[mighelone]

Hi Doug,

your technique seems very interesting, maybe a little bit complicated.

However the Pey-Ying's observation is true, in fact extruding 2D surface for irregular geometry I suppose to be very hard!

Unfortunately in the open source world a free hexa mesh generator doesn't exist yet, like OpenFoam for solver or paraview, opendx for post-processing.

Michele

[gdbaldw]

Pei,

I'm using manifolds, stretching the surface as it is moved away from the body. I developed a Python script for manifolds. I'm begining a meshing project where I'll be able to post images over the next week or so, which would be the best way I think to show how to use the monifolds script.

Doug

[hsieh]

Hi, Doug,

It will be great if you can post the steps/images on the internet - much easier to understand. Thanks for the effort!

pei

[7islands]

I second Pei. Doug, would it be too much of a work to collect the materials you posted and attach them to the Wiki?

Takuya

[hellorishi]

Hello,

I am impressed with the ease of generating hexamesh with blockMesh for simple geometery. However I am not sure how to get my IGES file to blockMesh format. My geometery consists of two pipes perpendicular to each other, however their intersection is a bit complicated: gradual expansion.

I will have to use splines to describe this intersection. Can anybody shed some light on how to get the geometery(IGES) in blockMesh format ?

Does somebody has a geometery file of blockMesh with splines in it? Maybe I could use manually convert IGES to blockMesh...

Thanks
Rishi

[lakeat]

My votes go to GridPro, ICEM and Gridgen

Blockmesh should better be improved to have kind of auto-optimization functions.
Is it that hard, given dozens of moving mesh functions are already available?

[jchawner]

Michele:

Free hex gridding is available in MegaCads - http://www.megacads.dlr.de/

But you really should try Pointwise ;-)

[vitor.geraldes@ist.utl.pt]

For me cfMesh (from c-fields.com ) is one of the best mesh generators for OpenFoam.

[13msmemusman]

Originally Posted by hellorishi

Hello,

I am impressed with the ease of generating hexamesh with blockMesh for simple geometery. However I am not sure how to get my IGES file to blockMesh format. My geometery consists of two pipes perpendicular to each other, however their intersection is a bit complicated: gradual expansion.

I will have to use splines to describe this intersection. Can anybody shed some light on how to get the geometery(IGES) in blockMesh format ?

Does somebody has a geometery file of blockMesh with splines in it? Maybe I could use manually convert IGES to blockMesh...

Thanks
Rishi

Use snappyHexMesh for complex geometries..... with STL files. Only disadvantage is you can not make a parametric Mesh.... I like blockMesh due to its parametric mesh creating abilities....

[NablaDyn]

For complex geometries and moderate quality: Netgen, Engrid, Snappyhexmesh (in my opinion these generators provide rather moderate or good quality meshes).

For very-high-quality (elliptic) hex meshes: MegaCads (GUI support)