CGNS Steering Committee

Telecon Minutes

The meeting was called to order at 2:00 Eastern time. There were 13 attendees, listed below.

The minutes of the 21 June were reviewed. Steve Legensky asked that two discussion items be added to the minutes: 1) We discussed version control and agreed on a new API software release process where we release once per year, with a beta release for new capabilities. 2) There was some discussion, with no conclusion, about what is sufficient information to consider a file CGNS compliant (additional discussion below). These items will be added to the minutes. The minutes were then approved as amended.

• Steering Committee Nominations - The Sverdrup representatives at AEDC indicated a willingness to represent the Air Force on the Steering Committee. This will be included in the discussion for the list of nominees to be presented at the end of the year.
  
  
• ISO Status - There was a meeting to review the preliminary ISO-STEP documentation which represents the migration of CGNS into an international standard. The Steering Committee should remain vigilant that the standards do not diverge. So far, it seems that CGNS and the ISO standard can remain compatible. The ISO-STEP proposal is due out for public comment in November. It is hoped that the CGNS community will actively review and keep the definitions from diverging.
  
  
• Documentation - Charlie Towne indicated that the SIDS has been updated, and is almost ready for release. There was some discussion about how to release the SIDS and API. It was decided to create a beta release of the software, and to make the SIDS documentation consistent with each release.
  
  
  • Version 2.0 Beta 1: SIDS with all changes prior to grid motion
  • Version 2.0 Beta 2: Add grid motion and time accurate
  • Version 2.0 Beta 3: Add other extensions
  
  In December, Version 2.0 Beta 3 will become the production version 2.0.

  Chris Rumsey has written a draft User's Guide which is being reviewed by Bob Bush and Diane Poirier. Ed Hall volunteered to review the draft also.

  Steve Legensky is working on an AIAA implementation paper. He will be sending out a brief survey to get feedback on how and where CGNS is being used. He is also collecting examples to demonstrate interchangeability of the files. Potential volunteers with examples include Ed Hall and Dave Schowalter. It was also mentioned that the AIAA Drag Prediction Workshop might provide a good demonstration of delivering grids, and potentially solutions, using CGNS.
  
  

• Support - Don Roberts discussed his experiences with Tecplot Talk, an e-mail forum we might use as a pattern for a CGNS group. ListBot could manage the forum, potentially at no charge. Diane will check into setting up a forum for CGNS.

  There were no replies to inquiries for user support focal point.
  
  

• Extensions
  
  
  • Hierarchical Structures - Michel Delanaye has submitted a proposal. Very limited feedback to date (Diane). It is on the web, and the deadline for comments is set for the end of September so the implementation can begin.
    
    
  • Chemistry - The proposal has been in review recently, with minor mods incorporated. A revised version will be posted on the web when the current reviewers are in concurrence. Armen Darian has requested to be included in the current review.
    
    
  • Gravity, Axi-symmetry, Rotating Coordinates - Are ready for implementation.
    
    
  • Liquid Spray - Armen Darian has a draft in circulation. Additional reviewers are needed. Steve Legensky volunteered to review. Hope to have a proposal ready to post in September.
    
    
  • Hanging Nodes - No progress. Steve Legensky has contacted Steve Karman and plans to discuss with M. Aftosmis.
    
    
  • Wall Functions - Bob Bush will try to revive this extension. Chris Rumsey, Ed Hall and Steve Legensky offered to be on the review team.
    
    
  • Turbomachinery Boundary Conditions - Bob Bush will try to revive this extension also. No volunteers to review.
  
  
• Additional Items - It is difficult to interrogate and edit a file. Ed Hall offered to look into acquiring utilities that facilitate this. Diane Poirier will send a code that reads a file and outputs its contents. It would also be nice to have an editing capability, and a graphical user interface into the file. This might allow creation of non-cgns compliant modifications to the file. This also raises the possibility of a 'validator' which checks for some set of minimal information required to make the file 'compliant'. Francis Enomoto has looked at XML, which might be useable as a CGNS browser since XML structures are similar to CGNS structures. He will try to map the SIDS into an XML format.

Bob Bush will set up the next telecon for mid October, the next meeting will take place at the AIAA conference in Reno in January.

Attendees