CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Meshing Format & General Technical (http://www.cfd-online.com/Forums/openfoam-meshing-technical/)
-   -   How to hex mesh geometry in STL format? (http://www.cfd-online.com/Forums/openfoam-meshing-technical/64458-how-hex-mesh-geometry-stl-format.html)

bigphil May 12, 2009 07:10

How to hex mesh geometry in STL format?
 
Hi,


I have geometry in the STL format, and I would like to hex mesh it.


Has any done this before, starting from a STL and finishing with a hex mesh?


Any advice would be much appreciated,
Philip

santos May 12, 2009 07:34

Hi Philip,

Have you tried snappyHexMesh? It does exactly what you need. Have a look in the User Guide to see how it can be used.

Regards,
Jose Santos

bigphil May 12, 2009 08:26

Hi Jose,

I read through snappyHexMesh in the manual.

Is it possible to use snappyHexMesh for meshing the geometry itself, as apposed to around the geometry like in the snappyHesMesh example?

I have a femur (thigh bone) which I would like to mesh.


Thanks for you reply,
If snappyHexMesh suits, that would be great!

Philip

santos May 12, 2009 09:15

Yes, its possible. You need to define the locationInMesh point in the region you are interested in, ie, inside the femur in you case.

Regards,
Jose Santos

bigphil May 12, 2009 09:21

Jose,


That's great. I didn't realise I could use snappyHexMesh to hex mesh objects.

I shall head off now, and try to learn snappyHexMesh.


Thanks very much for the advice,
it is much appreciated.

Best Regards,
Philip

:)

wendywu June 30, 2009 22:55

Hi, Jose,
Now I am facing a weird problem.
I am going to hex mesh the flow field in a screw extruder.
I blockMeshed the barrel back ground . it worked.
I then tried to snappyHexMesh the field between the screw and the barrel.
I defined the location in mesh , but when I run sHM, it always exited with saying:
Point (x x x) is not inside the mesh or on a face or edge.
Bounding box of the mesh:(-13.1 -13.1 0) (13.1 13.1 197)
I tried several point , even though I pretend to mesh the area inside the screw.
it does so also. I have tried to avoid the point on the face or edge.
I can not solve the problem. Would you give me some hint?
Thank you.

Wendy

santos July 1, 2009 04:37

Make sure the dimensions of blockMesh and STL meshes are consistent (eg. m or mm). Its hard to help without extra info on your mesh!

Regards,
Jose Santos

wendywu July 2, 2009 11:40

Now the problem is, when I run sHM, it stops with the error information:
#0 Foam::error::printStack(Foam::Ostream&) in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted: [0xb8076400]
#3 Foam::meshRefinement::markSurfaceCurvatureRefineme nt(double, int, Foam::List<int> const&, Foam::Field<Foam::Vector<double> > const&, Foam::List<int>&, int&) const in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libautoMesh.so"
#4 Foam::meshRefinement::refineCandidates(Foam::Vecto r<double> const&, double, Foam::PtrList<Foam::featureEdgeMesh> const&, Foam::List<int> const&, bool, bool, bool, bool, int, int) const in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libautoMesh.so"
#5 Foam::autoRefineDriver::surfaceOnlyRefine(Foam::re finementParameters const&, int) in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libautoMesh.so"
#6 Foam::autoRefineDriver::doRefine(Foam::dictionary const&, Foam::refinementParameters const&, bool) in "/home/xhw/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libautoMesh.so"
#7 main in "/home/xhw/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/snappyHexMesh"
#8 __libc_start_main in "/lib/tls/i686/cmov/libc.so.6"
#9 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream::versionNumber, Foam::IOstream::compressionType) const in "/home/xhw/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/snappyHexMesh"
Floating point exception

I am considering if it is caused by shortage of memory space?
Thank you.

Wendy

wendywu July 2, 2009 23:36

I just tried another simpler case. it is just a cylinder inside a bigger rectangular container.

when sHM for several iterations, it stoped with information: killed.
no sHM results created.
Anybody has such experience?
Thank you.

Wendy

wendywu July 6, 2009 12:29

sHM , refinement level
 
I modified refinement level , it worked finally.
but what is the problem that it works well with lower level and doesn't work with higher level? I still want to get better mesh so I would prefer higher refinement level.
Many thanks to any advice.

Wendy


All times are GMT -4. The time now is 20:29.