how to import the CAD drawing into openfoam
 

Hi,

I'm a beginner user of the openfoam, and I have a project of modeling flow patterns in a membrane bio-reactor for waste water treatment using finite volume method. I've built the goemetry using two softwares (Auto-CAD 2012 and SolidEdge) and saved them according to their normal format (dwg or par) respectivley. The problem is that I need a software that could help me to generate mesh according to the Finite volume method so I can import the drawing afterwards into the OpenFOAM with their generated meshes. I've looked over other topics in the forum but I found many softwares which are not compatible with both softwares I used (either Autocad or openFOAM).

What I require is your suggetions within any simple software that can help in this phase (generating mesh and converting it into openFOAM) and I would more pleased if you could pass the tutorial of how I can use this software.

Many Thanks,
SE

Hi,

both CAD-programms should be able to create STL-files http://en.wikipedia.org/wiki/STL_(file_format) to use snappyhexmesh (SHM)
http://www.openfoam.com/docs/user/sn...#x26-1510005.4 http://www.openfoam.com/features/mesh-generation.php
http://www.tfd.chalmers.se/~hani/kur...on_2010_OP.pdf

otherwise you can use gmsh, netgen, salome, engrid, discretizer calculixs(preprocessor) to name a few programs (all are even for free of charge).
http://web.student.chalmers.se/group...SlidesOFW5.pdf =>Engrid based Tutorial
http://www.openfoamworkshop.org/08/p...FOAMCharts.pdf

http://www.caelinux.org/wiki/index.php/Doc:CAETutorials see=>Salome&Openfoam tutorial "a little bit outdated but you should be able to transfer to actual releases"

http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2010/ might be a good source as well
=> Mesh generation with m4/blockMesh, snappyHexMesh, and converters see link mentioned above

another file-formats that most CAD-programs support are IGES http://en.wikipedia.org/wiki/IGES and STEP http://en.wikipedia.org/wiki/ISO_10303

via IGES, STEP or STL you are able to export to one of the many free preprocessors which can be converted http://www.openfoam.com/features/mesh-conversion.php => gmshToFoam, netgenNeutralToFoam ideasUnvToFoam =>unv by salome

Hi,

the easiest way is probably to export your modell as stl-file.
Then use snappyHexMesh (mesh-tool in openFoam) to create your mesh.

Many Thanks for your kind reply, I've downloaded netgen v.4.4 and I imported the geometry but while generating the mesh, an error message appears that some libraries are missing. Any suggestions?!

Hi
 

Many Thanks for your kind reply, I've downloaded netgen v.4.4 and I imported the geometry but while generating the mesh, an error message appears that some libraries are missing. Any suggestions?!

You have to copy the stl file into constant/triSurface/
Have a look at motorbike tutorial. You will find all necessary commands in there (Allrun).

Sorry for reopening this thread but where can I find the motorbike tutorial?

FreeCAD
 

Generating grid can be really challenging by using openfoam's native tools.

You can create your grid if the geometry is fairly simple by using blockmesh or snappyhexmesh if you have your geometry in stl format.

In both cases, it's still quite difficult, because the learning curve is incredibly steep for openfoam's meshing tools, at least that's what I think so. I use another software to create my grid in most of the cases, I recommend the same for you, at least at the beginning so that you don't stuck.

FreeCAD has an experimental workbench which integrates with OpenFOAM directly,

I have a xp-pen Artist 12 Pro Art Drawing Pad and the FreeCAD app works fine on it.

Incompressible/simpleFoam