CFD General Notation System
Latest News

August 26, 2009: Version 3.0.5 (Beta) released. This Beta version is intended for users to perform preliminary testing. Many changes have been made from 2.5, but a few of the more noticeable ones include the following: (1) Build system has been changed from autotools to CMake, (2) Moving forward the HDF5 back-end will have preference, (3) cgnscalc and cgnssh have been disabled since they do not currently work. The new beta can be downloaded from the subversion repository at SourceForge.

August 22, 2009: Version 2.5.4 released. This release fixes a long standing issue of memory leakage in the CGNS library when closing a file or deleting a node. It also removes the internal storage of element data when reading and writing, and uses the user supplied buffer instead. In the case of partial reads and writes however, the element data is currently reloaded into memory to do the operations.

March 11, 2007: Version 2.5.3 released. This version changes the mispelled Celcius to Celsius, fixes handling of soft links when rewriting the CGNS file, and fixes a number of gcc compiler warnings.

September 11, 2007: A new instructor-led AIAA short course is being offered starting at the Aerospace Sciences Meeting in Reno, NV, January 5-6, 2008: "Effective Use of the CFD General Notation System (CGNS) for Commercial and Research Applications." A description can be found by going to: www.aiaa.org. Click on "Courses & Training", then "Schedule". The CGNS course is listed under the Heading: January 2008. Or go directly to: Summary of Short Course.

September 7, 2007: Version 2.5 taken off beta status. This new release adds "CG_" prefixes to the C preprocessor defines MODE_xxx, Null, and UserDefined. For example, MODE_READ is now CG_MODE_READ and Null is now CG_Null. The old defines are still currently supported. Support has been added to build the cgns library as a DLL under Windows. The NormalIndex arguments to cg_boco_info, cg_boco_normal_write are now optional (pass as 0 or NULL to ignore). Moved some of the CGNS utility programs, such as cgnscheck, to the subdirectory 'tools' in the cgns distribution. This may now be built without building cgnstools. Also, final release of cgnsib_2.4 made (primarily an update of version number from 2.42 to 2.46, and some minor bug fixes). The last digit on the version number is now ignored when reporting that a file was created with a newer version than the current library. Finally, in cgnstools, changed cgnsplot to use a tree layout instead of lists, and added a cutting plane for viewing mesh cross-sections. Fixed a long standing bug in cgns_interpolate which was causing that program to work incorrectly or crash. Also added a VTK file export routine for CGNS files.

October 5, 2006: Version 2.5 (beta) of the CGNS library has been released (cgnslib_2.5-1.tar.gz). This fixes problems with partial read and writes, and adds some additional capabilities (goto operation enhancements, type names, new cgns file checker, setting path to search for links, and new routine for configuring CGNS). Documentation is not available yet. Look in the "tests" subdirectory at "test_partial.c" and "test_goto.c" for examples of the use of these routines. In addition, there are 2 other new releases for download from SourceForge: (1) cgnslib_2.4-5.tar.gz: This release fixes some problems with ADF on Windows 64 bit machines, and adds a -64 option to the configure.bat file. (2) cgnstools-2-5-1.tar.gz: Adds support for CGNS version 2.5. Configures the Tcl/Tk GUI to use the current color scheme rather than a "Windows" type color scheme. Fixes some minor bugs and adds some improvement to the cgnscheck program. Allows reading of both HDF5 and ADF - based CGNS files (requires the adf2hdf and hdf2adf convertor programs).

Spring, 2006: There are two special CGNS "events" planned for the American Institute of Aeronautics and Astronautics (AIAA) meeting being held 5-8 June 2006 in San Francisco. The first is a Panel discussion, tentatively titled "CGNS Practical Applications in CFD". This will occur during the regular AIAA sessions at the conference. The second is a "CGNS Tutorial Session", currently scheduled for Wednsday, 7 June 2006 in the evening. This session will be conducted in two parts: (1) Basic usage of CGNS (including examples for structured and unstructured grids), and (2) Advanced topics (tentatively including HDF-5 usage, parallel implementation, and SIDS high level representation). The tutorial session will be taught by five experienced users/developers of CGNS and will be a great way to either get a basic introduction or to refine your knowledge of CGNS. Note that AIAA charges a registration fee for conference attendance, but there is no additional fee to attend the CGNS events. More information about the AIAA conference can be found at: www.aiaa.org. Click on "Conferences & Events", then click on "36th AIAA Fluid Dynamics Conference and Exhibit".

August 23, 2005: New releases of Version 2.3 and 2.4 of the CGNS library and CGNStools. This is the final release for Version 2.3 - Version 2.4 is now the official version. The CGNS library releases fixed a bug in cg_family_write and others where the wrong file (when multiple are open) might be accessed or a segfault occur. Added unstructured mesh rind to Version 2.4, and support for that in CGNSplot and cgnscheck. Improved the Fortran to C interface, particularly under Windows, Also fixed some minor bugs in the CGNStools and improved the cgnscheck program.

August 8, 2005: CGNStalk discussion list moved from cgnstalk@grc.nasa.gov to cgnstalk@lists.nasa.gov.

May 14, 2005: Version 2.4 (Revision 2) of the CGNS library released. The HDF5 interface (ADFH) may now be selected at build time with the configuration script. Fixed some bugs.

December 2, 2004: Version 2.4 (beta) of the CGNS library has been released. This version includes the extensions by Intelligent Light. These extensions include 8 base units, partial read/write, Electromagnetics, 1tot1 connectivity properties, and extensions to the FamilyBC, BCDataSet and UserDefinedData. Preliminary documentation for these extensions in the form of PDF files is also available for download. 

October 1, 2004: Released an update to Version 2.3 of the CGNS library. This update fixes some problems with MLL routines returning the wrong error code (or terminating prematurely). Also, checks are now performed when creating a CGNS file to prevent writing a file which fails to read. A new version of cgnstools has also been released with improvements to both adfviewer and cgnsplot. The cgnscheck program has been significantly improved. It should now check the validity of all CGNS 2.3 nodes. 

March 22, 2004: ADFH has been released as beta. This is a complete implementation of CGNS using HDF5 instead of ADF. 

January 22, 2004: Version 2.3 of the CGNS library has been released. The major changes in this version over that of 2.2 is a significant speedup in reading and writing when dealing with a large number of zones and the reimplementation of ElementList and ElementRange for specifying boundary conditions. 

December 13, 2003: An initial prototype has been released which replaces ADF with HDF5. Thanks to Marc Poinot at Onera and Greg Power's group at Arnold. The source is currently only available with CVS as module adfh. 

September 28, 2003: CGNS library Version 2.3 beta release. This version currently adds no additional functionality to that of Version 2.2, but speeds up read/write times by orders of magnitude when a large number of zones are present. 

May 10, 2003: CGNS Version 2.2 has been released.

May 3, 2003: The CGNS source code is now available as a download of the latest release or anonymous CVS access to the current beta version at SourceForge.net. There is now a GNU configure script for configuring compiler options.

January 23, 2003: The CGNS documentation and Technical Papers link now points to a single website location at NASA Glenn. All documentation, papers and the minutes of the CGNS Steering Committee meetings are available there.

September 18, 2002:  Minutes of the CGNS Steering Committee meetings and teleconferences are available at the NASA Glenn website. 

January 16, 2002: AIAA 2002-0752, "CFD General Notation System (CGNS): Status and Future Directions" presented at the 40th Aerospace Sciences Meeting & Exhibit, Reno, Nevada.

December 1, 2000: Release of Version 2.0 beta 2 which supports grid motion and iterative or time accurate data.

October 31, 2001: Review the new "User's Guide to CGNS" created by Chris Rumsey of NASA Langley Research Center.

January 18, 2002: The latest revision of the draft ISO standard is available for review.

October 18, 2000: CGNS has now its own discussion group. Users can exchange opinions and experiences via CGNS Talk.

March 15, 2000: Added support for MIXED element sections.

January 10, 2000: The CGNS Steering Committee becomes a sub-committee of the AIAA Committee
on Standards.

January 12, 2000: AIAA 2000-0681, "Advances in the CGNS Database Standard for Aerodynamics and
CFD." presented at the 38th Aerospace Sciences Meeting & Exhibit, Reno, Nevada.

October 14, 1999: The CGNS Steering Committee Charter has been unanimously adopted at the CGNS Meeting at UTRC, East Hartford.

September 1999: The CGNS Library and the ADF File Browser are now available on Windows NT and Linux !!!