Sig Turbomachinery Utilities CGNS Converters

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Revision as of 04:04, 8 November 2008 by MBeaudoin (Talk | contribs)

1 Introduction

The CFD General Notation System (CGNS) file converters cgnsToFoam and foamToCGNS allow for the conversion back and forth between OpenFOAM cases and files in CGNS format.

The converters support:

  • import and export of grid information
    • importing structured and unstructured grid from CGNS format file
    • exporting OpenFOAM grid format to unstructured grid CGNS format
  • import and export of boundary conditions information, including periodic or cyclic BCs
  • import and export of flow solutions


Using CGNS files, one can easily transfer CFD information like mesh and flow solutions between OpenFOAM and many commercial CFD applications (mesh generators, solvers, etc).

For more information on the CGNS file format, visit the following site: http://cgns.sourceforge.net/

2 Installing the CGNS converters

The CGNS file converters are available from the SourceForge.NET site http://openfoam-extend.wiki.sourceforge.net/ through a Subversion source code repository.

The converters source code currently resides in the Breeder section of the repository, under the TurboMachinery OpenFOAM Special Interest Group (OSIG) section.

For more information on the structure of the Subversion repository for the openfoam-extend project on SourceForge.NET, see the following presentation from the 2nd OpenFOAM Workshop: Open Subversion Repository Access For OpenFOAM

For browsing the openfoam-extend Subversion repository, follow this URL: http://openfoam-extend.svn.sourceforge.net/viewvc/openfoam-extend/

The CGNS converters are based on the following components:

  • cgnslib_2.5  : CGNS Mid-Level library
  • cgnstools_2.5 : optional package from http://cgns.sourceforge.net/. Tools for viewing and editing CGNS files
  • libcgnsoo_3.0 : C++ wrapper for the CGNS Mid-Level library
  • cgnsToFoam  : CGNS file conversion to OpenFOAM
  • foamToCGNS  : OpenFOAM conversion to CGNS file


2.1 Downloading the CGNS converters and companion libraries

The easiest way to retrieve the CGNS converters source code is to download the whole TurboMachinery section of the Breeder from the openfoam-extend Subversion repository.

  • For OpenFOAM 1.5
cd $WM_PROJECT_USER_DIR
svn checkout https://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder_1.5/OSIG/TurboMachinery
  • For OpenFOAM 1.4.1
cd $WM_PROJECT_USER_DIR
svn checkout https://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder/OSIG/TurboMachinery


It is also possible to download the converters, companion libraries and tutorial individually. For example, for OpenFOAM 1.5:

  • The CGNS converters:
svn checkout https://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder_1.5/OSIG/TurboMachinery/applications
  • The companion libraries:
svn checkout https://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder_1.5/OSIG/TurboMachinery/src
  • The test cases:
svn checkout https://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder_1.5/OSIG/TurboMachinery/tutorials

NB: if the relative installation locations of the converters components are modified, the files Make/options for cgnsToFoam and foamToCGNS will need to be adjusted accordingly.

2.2 Compiling the companion libraries

2.3 Compiling the applications

3 Testing the CGNS converters

4 Basic documentation

4.1 cgnsToFoam

4.2 foamToCGNS

5 Use cases