OpenFOAM Mesh Conversion Test

OpenFOAM provides many libraries for converting meshes generated in any of the major common formats. Listed below are reported these utilities.

Library	Conversion from:
`fluentMeshToFoam`	FLUENT mesh .msh, both 2D and 3D
`starToFoam`	Mesh STAR-CDPROSTAR
`sammToFoam`	Mesh STAR-CD SAMMA
`gambitToFoam`	GAMBIT mesh .neu
`ansysToFoam`	I-DEAS mesh ANSYS.ans
`cfxToFoam`	CFX mesh .geo
`ccm26ToFoam`	File STAR-CCM
`gmshToFoam`	Gmsh file .msh
`kivaToFoam`	KIVA3v mesh
`netgenNeutralToFoam`	Netgen mesh
`tetgenToFoam`	Tetgen .ele, .node and .face meshes

In order to convert a mesh to OpenFOAM format it suffices to make the following steps:

Create an OpenFOAM directory case structure:

mkdir casename
mkdir casename/system
mkdir casename/constant
mkdir casename/constant/polyMesh
mkdir casename/0

Create the controlDict file which contains temporal evolution information (see the OpenFOAM User Guide):

vi casename/system/controlDict

Create the files for setting the solutor and other stuffs (see the OpenFOAM User Guide):

vi casename/system/fvSchemes
vi casename/system/fvSolution

Run the appropriate library:

library < caseroot > < casename > < meshfile >
for example, if the case has been created in the current directory:
fluent3DMeshToFoam . casename file.msh

 




Below is shown the result of a simple 3D GAMBIT mesh conversion. The GAMBIT mesh was exported as a .msh file and the OpenFOAM fluent3DMeshToFoam utility was used. 









The figure shows (half) a simple 3D geometry meshed with GAMBIT.











The figure shows the above (full) GAMBIT mesh converted by OpenFOAM.


OpenFOAM mesh converters can be used even in case of complicated geometries. Next is shown a mesh in OpenFOAM format after having converted it from FLUENT. The geometry describes a train coach and was designed for studying air conditioning flow inside the vehicle.
 









The figure shows the surface of a train coach mesh converted by OpenFOAM from a FLUENT format.
 

The next example shows how to convert a mesh generated by OpenFOAM to a FLUENT format. The steps to do are the following.


Use the foamMeshToFluent utility:


foamMeshToFluent < caseroot > < casename >  



The resulting mesh is written out in a file placed in the fluentInterface subdirectory of the case directory, i.e. casename/fluentInterface/casename.msh . The converted mesh can be read by GAMBIT. To do this, one has to read the mesh in FLUENT, save it as a  .cas  file and read it back into GAMBIT, importing as FLUENT 5/6  .cas  2D or 3D file.











The figure shows a simple 3D mesh generated by OpenFOAM.











The figure shows the above OpenFOAM mesh converted to a FLUENT format.