# Presentation: 532342

## Status of Fluid Dynamics AP

- January 17, 2001

## 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.

## 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)

## 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

## CGNS Registered UsersP-Member Countries

## 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.

## Operating Relationships

**ISO Standards Organization**

**CGNS Steering Committee**

**Fluid Dynamics Standards Initiative**

- Intellectual content of the CGNS standard (SIDS)
- ADF libraries
- Mid-level libraries

- Map the CGNS content into the ISO process
- Build international support

- Integrate the fluid dynamics standard requirements with other ISO standards

**We will work with on the existing CGNS Steering Committee, and the users they represent, to build international consensus for the proposed standard.**

## 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)

## 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

## 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

## 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

## 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

## Structure of the Fluid Dynamics Standard

**AP2xx**
**Fluid Dynamics Data**

**Part 1xx**
**CFD Models**

**Part 5a**
**Mesh-Based Data**

**Part 5b**
**Numerical Analysis**

**Part 5x**
**Mesh-Based Topology**

**Part 50**
**Mathematical Constructs**

**EXISTING**

**NEW**

**Part 21**
**Clear-Text Encoding**

**Part 209**
**Finite-Element Analysis**

**Part 203 Geometry**

- Each of the new parts must be carried individually through the approval process.
- The lower-level parts will lead the way.

**Usage Guide for AP2xx**

- Extend to include binary data

## Major EventsSince 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

## ISO Organization

**ISO Organization**

**ISO**

**TC 184**

**SC4**

**WG3**
**Product**
**Modeling**

**WG4**
**Qualification **
**& Integration**

**WG8**
**Mfg. Mgmt Data**

**. . .**

**. . .**

**WG2**
** ****Parts Library**

**T9**
**Eng’r’g**
**Analysis**

- TC 184 – Industrial Automation Systems and Integration

- SC 4 – Industrial Data

## STEP Standards Development Life Cycle

**Preliminary Work Item**

**New Work Item**

**Industry Review Draft**

**Committee Draft**

**Draft International Std**

**Final Draft International Std**

**International Standard**

**Amendments or Technical Changes**

- Nov 1999

- Feb 2001

- Feb – June 2001

- June - Dec 2001

- 2003-4?

**6**

**5**

**4**

**3**

**2**

**1**

## Current Plans and Schedule

**These plans are tentative, as Boeing budgets for 2001 have not been finalized.**

**2001 Q1**

**2002 Q1**

**2001 Q4**

**2001 Q3**

**2001 Q2**

- AP 2xx

- Information Rqmts

- ARM Validation Rpt

- Interpretation

- WD Review

- CD Ballot

- Part 1xx

- WD Review

- CD Ballot

- Part 5x

- CD Ballot

- Part 5a

- WD Review

- CD Ballot

- Part 5b

- WD Review

- CD Ballot

## 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**