Status of the ISO-STEP Initiative for CGNS-Based Fluid Dynamics Standard

Presented to the AIAA CGNS Subcommittee
January 9, 2001

Raymond R. Cosner
Senior Technical Fellow
Boeing, Phantom Works
St. Louis, MO
(314) 233-6481
Raymond.R.Cosner@Boeing.com

What Is STEP?

• STEP is an acronym
  • STandard for the Exchange of Product model data
• Formal name is ISO 10303
  • Industrial automation systems and integration
  • Product data representation and exchange
  • Intended (eventually) to cover the complete life cycle of all industrial products
• PDES is Product Data Exchange using STEP
  • PDES is the U.S. effort, administered through the IGES/PDES organization, to support the development and deployment of the international STEP standard

STEP Approach

• The most viable solution:
  • public NOT proprietary data model;
  • supports extension for additional application;
  • has publicly defined interface/access mechanisms;
  • usable and stable over the life span of the products and their supporting information;
  • designed and validated to industry defined needs;
  • allows CAD/CAM/CAE industry to construct a compatible suite of engineering software.

Four Levels of Exchange

• Level 1 - Physical file transfer
  • communication between two remote processes in which data is exchanged via a sequential file of an agreed upon format.
• Level 2 - Shared memory access exchange
  • communication between two concurrent processes in which data is exchanged via agreed upon data access processes. There is no assertion of data persistence.
• Level 3 - Shared database access exchange
  • communication between two or more asynchronous processes in which data is exchanged via agreed upon access processes to a persistent data repository.
• Level 4 - Knowledge-based data exchange
  • communication between two or more asynchronous processes in which data is exchanged via agreed upon access mechanisms to a persistent repository supporting both product data and knowledge of processes related to use of that data. Further definition of this concept and any supporting activity is a future work item.

Differences between ISO-STEP and CGNS

ISO-STEP is based on ...

• Strong link to Product Data Management
  • Record of all data sources, persistent links if possible
• Commonality and re-use of existing data structures to maximum extent possible
  • E.g., re-use data structures from AP203 (geometry), AP209 (finite element analysis), and AP232 (technical data exchange)
• ASCII data exchange
  • We will need to extend ISO-STEP to provide binary data exchange as an option

Major Events

Since previous committee meeting, June 2000

• Review draft ISO-STEP standard with CGNS Steering Team members (July 6-7, Seattle, WA)
  • General approval of then-current state; some issues identified
• Initial draft of standards documentation completed (Sept 2000)
  • Work mainly accomplished by Peter Wilson (Boeing - Seattle)
  • Incomplete, but contains all technical content of SIDS as of August 2000
• ISO meeting (October 16-20, Charleston, SC)
  • Cosner presentation to Change Management Board
    • Focused on scope, component parts, schedule of the Fluid Dynamics AP
• Technical Workshop (December 11-14, Seattle, WA)
  • Define the structure of the Fluid Dynamics AP
  • Continue defining the organization and content

ISO Organization

Structure of the Fluid Dynamics Standard

STEP Standards Development Life Cycle

• Preliminary Work Item: Nov 1999
• New Work Item: Feb 2001
• Industry Review Draft: Feb-June 2001
• Committee Draft: June-Dec 2001
• Draft International Std
• Final Draft International Std
• International Std: 2003-4?
• Amendments or Technical Changes

Approval Process

• Passage through each "gate" requires a specified number of favorable votes
  • One country = one vote
  • P-Member countries are voting members (there also are observers)
• Required number of votes becomes more stringent at each "gate"
• To gain approval, it is essential to have supporters in most (all) of the P-member countries
  • There are CGNS users in each P-member country
• P-Member Countries
  • Australia
  • Canada
  • China
  • France
  • Germany
  • Italy
  • Japan
  • Korea (Republic of)
  • Netherlands
  • Norway
  • Portugal
  • Russia
  • Spain
  • Sweden
  • Switzerland
  • United Kingdom
  • United States

Operating Relationships

• ISO Standards Organization
  • Integrate the fluid dynamics standard requirements with other ISO standards
• Fluid Dynamics Standards Initiative
  • Map the CGNS content into the ISO process
  • Build international support
• CGNS Steering Committee
  • Intellectual content of the CGNS standard (SIDS)
  • ADF libraries
  • Mid-level libraries