Status of Fluid Dynamics AP

1. Status of Fluid Dynamics AP January 17, 2001

2. Background • Boeing has taken responsibility for leading development of an ISO-STEP standard for archive and exchange of digital data in fluid dynamics • Initial Boeing decision taken in February 1998 • Briefing to SC4/WG3 at their meeting in January 1999 • This effort is being led within Boeing by Ray Cosner • This effort is based on the existing CGNS standard for CFD data.

3. Background and Related Activities • CGNS was developed as a CFD data storage and exchange standard by NASA, Boeing, and (then) McDonnell Douglas • CGNS = “CFD Generalized Notation System” • Work was performed 1994-99, largely funded by NASA • The CGNS Steering Committee was established to coordinate the further development of this standard. • CGNS is gaining support • Commercial vendors have committed to support: Fluent, Adapco, Numeca, ICEM-CFD, Intelligent Light, Pointwise • Major aerospace organizations are participating: Boeing, Rolls Royce (UK, US, GE), British Aerospace, USAF, NASA, UTRC • CGNS users in every ISO SC4/WG3/T9 P-member country • CGNS Steering Committee now operates as a subcommittee of the American Institute of Aeronautics and Astronautics (AIAA)

4. 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

5. CGNS Registered UsersP-Member Countries

6. Strategy • Adapt CGNS as the kernel of an ISO standard for storage and exchange of digital data in fluid dynamics • Utilize current CGNS structure and concepts to the maximum extent that is practical • Use current CGNS user base as core supporters for the ISO Fluid Dynamics AP development • Utilize a two-stage strategy • First: Establish an AP for CFD data • Build on existing CGNS, which is fairly mature for CFD • Second: Extend the AP to other types of fluid dynamics data • Wind tunnel, flight test, hydrodynamics, etc.

7. Operating Relationships ISO Standards Organization CGNS Steering Committee Fluid Dynamics Standards Initiative • Integrate the fluid dynamics standard requirements with other ISO standards • Map the CGNS content into the ISO process • Build international support • Intellectual content of the CGNS standard (SIDS) • ADF libraries • Mid-level libraries We will work with on the existing CGNS Steering Committee, and the users they represent, to build international consensus for the proposed standard.

8. Scope (AP FD) • digital data on structured and unstructured grids describing steady or unsteady fluid dynamics flowfields • data describing the fluid dynamics model including grid description, grid inter-connectivity • boundary conditions, and modeling parameters • data from solutions of equation sets commonly used in fluid dynamics analysis • Navier-Stokes equations, Euler equations, linear and nonlinear potential flow equations, small-disturbance equations, boundary layer equations, and stream function equations • single-phase flow of a liquid or a gas • laminar flow, transitional flow, turbulent flow (direct representation of turbulence, or represented by Reynolds-averaged data) • incompressible or compressible flow • unsteady flow • perfect gas, or variable chemical composition (equilibrium flow, frozen flow, or finite-rate chemical reactions)

9. Scope (AP FD) • data regarding the exchange of energy by molecular transport including convection and conduction • rotating flowfields (e.g., turbomachinery) • inertial and rotating frames of reference; • Newtonian transport laws; • reference to product geometry; • administrative information necessary to track the approval and configuration control of the analysis of a product

10. Out of Scope (AP FD) • representations of geometry • gross flow in networks (e.g., piping and ducting) • the use that application programs may make of the data • the means by which application programs modify the data • the form in which the data is stored internal to an application • The validity, accuracy and completeness of the data for a particular purpose are determined entirely by the applications’ software

11. Out of Scope – for the present NOTE : The following are outside the scope of this edition of this part of ISO 10303 but are expected to be within the scopes of later editions of this part: • two- and three-phase flow • free surface flow • non-continuum flow (e.g., direct simulation Monte Carlo data) • data from non-analytical sources (e.g., experimental simulation such as wind tunnel or water tank testing, and product test such as flight test or sea trials) • data regarding the exchange of energy by radiation • non-Newtonian transport laws • electro-magnetic interactions with a fluid • Plasmas; MHD

12. Existing Documents • AP FD • Current draft of the AP for Fluid Dynamics • IR 5w – Numerical Analysis and Support • IR 5s – Mesh-Based Topology • Harmonizes overlap between CFD resources in 5w and EACM resources in 5x • Defines structured and unstructured meshes • Expect to be used by AP-FD (Fluid Dynamics), EACM, and Part 209 • These documents will be restructured to conform to ISO objectives for modular standards • Draws on material from AP203, AP209, AP232, Part 21, Part 50, others • Five new documents: AP2xx, Part 1xx, Part 5a, Part 5b, Part 5x

13. Structure of the Fluid Dynamics Standard EXISTING Usage Guide for AP2xx Part 209 Finite-Element Analysis AP2xx Fluid Dynamics Data Part 203 Geometry NEW Part 1xx CFD Models Part 50 Mathematical Constructs Part 5a Mesh-Based Data Part 5b Numerical Analysis Part 5x Mesh-Based Topology Part 21 Clear-Text Encoding Each of the new parts must be carried individually through the approval process. The lower-level parts will lead the way. Extend to include binary data

14. Major EventsSince 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 CGNS SIDS as of August 2000 • ISO meeting (October 16-20, Charleston, SC) • 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

15. ISO Organization ISO . . . TC 184 – Industrial Automation Systems and Integration TC 184 . . . SC4 SC 4 – Industrial Data WG3 Product Modeling WG4 Qualification & Integration WG2 Parts Library WG8 Mfg. Mgmt Data T9 Eng’r’g Analysis

16. STEP Standards Development Life Cycle Amendments or Technical Changes 6 International Standard 2003-4? 5 Final Draft International Std 4 Draft International Std 3 Committee Draft June - Dec 2001 Industry Review Draft Feb – June 2001 2 New Work Item Feb 2001 1 Preliminary Work Item Nov 1999

17. Current Plans and Schedule These plans are tentative, as Boeing budgets for 2001 have not been finalized. 2001 Q1 2001 Q2 2001 Q3 2001 Q4 2002 Q1 AP 2xx Information Rqmts WD Review CD Ballot ARM Validation Rpt Interpretation Part 1xx WD Review CD Ballot CD Ballot Part 5x Part 5a WD Review CD Ballot Part 5b WD Review CD Ballot

18. Things to Watch • Need to keep working on international support • Need to keep the current CGNS users engaged • Work with the CGNS Steering Committee to accomplish this No problems visible that threaten success of this project. CGNS and ISO-CGNS documents are available at http://www.cgns.org