CPEX

The CGNS Proposals for Extension (CPEX) is a design document or documents that describe a new feature for CGNS. The CPEX should provide a concise technical specification of the feature and a rationale for the feature. The CPEX is intended to be the primary mechanism for proposing new features and for collecting community input on an issue. The CPEX author is responsible for building consensus within the community and documenting dissenting opinions.

The CPEX editors assign CPEX numbers and change their status. All CPEX-related email should be sent to cgnstalk@lists.nasa.gov and a CPEX issue should be created on cgnsorg.atlassian.net to track review and CPEX evolution. Each CPEX must have a champion - someone who writes the CPEX, shepherds the discussions, and attempts to build community consensus around the idea. The CPEX champion must first try to determine if their idea is appropriate for a CPEX. (Small enhancements or patches may not need a CPEX.) If a CPEX is appropriate, the champion must write a proposal, following the guidelines below. A CPEX number is then assigned. This is typically followed by a period of discussion, comments, input, and consensus-building, as well as an in-depth critical review. The CGNS Steering Committee ultimately votes for or against adoption.

The proposals listed below that were “not accepted” never made it to implementation, possibly because of lack of unified support, incomplete details, lack of champion involvement in the process, or because they were not generalizable to a wide enough class of problems. It is possible to resurrect and/or revise and resubmit older proposals. Some additional guidelines regarding changes or additions to the CGNS standard can be found in the CGNS Steering Committee Charter.

The CPEX should include the following information:

• Name(s) and organization(s) of proposer(s)

• E-mail contact information

• General description of extension

• Reason or need for extension

• Detailed description of extension using similar documentation style found in the SIDS

• File Mapping description of Node Attributes, following the prescription given in existing Node Description Documentation

• Specific example(s) of extension

Note

It is possible for a feature to be implemented in the SIDS and Filemap documentation, but not yet be implemented in the MLL software. If/when this occurs, it means that an “official” CGNS file can still be constructed with this feature, but the user must make use of means other than the MLL to accomplish it.

A primary requirement of all proposals for modifications will be to support and maintain code compatibility. No additions or changes to the CGNS standard will be adopted - without overwhelmingly compelling reasons - which invalidate existing software or data.

Note

CPEX work flow and requirements are new as of 09/2009, so older proposals may be missing some of the required information.

Comments on proposals should be sent to cgnstalk@lists.nasa.gov and/or written directly in the comment section of the jira issue.

Note

The CPEX is loosely patterned after the Python-based PEP (Python Enhancement Proposal). We gratefully acknowledge their well-documented methodology.

CPEX0046

CPEX#	0046
Scope	Particle Data
Contacts	Thomas Hauser
Documentation	CPEX-0046 Particle Data
Date First Posted	Mar.26.19
Date of Last Revision	Mar.26.19
SIDS Status	under review
Filemap Status	under review
MLL Status	under review

CPEX0045

CPEX#	0045
Scope	Polynomial Data and Curved Grid Elements
Contacts	Koen Hillewaert
Documentation	CPEX-0045 High Order
Date First Posted	Mar.26.19
Date of Last Revision	Jun.25.19
SIDS Status	accepted; awaiting implementation
Filemap Status	accepted; awaiting implementation
MLL Status	accepted; awaiting implementation

CPEX0044

CPEX#	0044
Scope	Encoding Functions
Contacts	Koen Hillewaert
Documentation	CPEX-0044 Encoding functions
Date First Posted	Mar.26.19
Date of Last Revision	Mar.28.19
SIDS Status	under review
Filemap Status	under review
MLL Status	under review

CPEX0043

CPEX#	0043
Scope	Family Hierarchy as a Tree
Contacts	marc.poinot@safrangroup.com; yoan.collet@numeca.com
Documentation	CPEX-0043-familytrees-v2.pdf
Date First Posted	Nov.06.18
Date of Last Revision	Jun.13.19
SIDS Status	implemented version 4.1
Filemap Status	implemented version 4.1
MLL Status	implemented version 4.1

CPEX0042

CPEX#	0042
Scope	Storing the Bounding Box of a Grid
Contacts	Mickael Philit
Documentation	CPEX-0042-boundingbox-v2.pdf
Date First Posted	Nov.06.18
Date of Last Revision	May.29.19
SIDS Status	implemented version 4.1
Filemap Status	implemented version 4.1
MLL Status	implemented version 4.1

CPEX0041

CPEX#	0041
Scope	NGON Modification Proposals
Contacts	Pierre-Jacques Legay
Documentation	NGON-CPEX-0041-v0.16.pdf
Date First Posted	May.05.17
Date of Last Revision	Sep.15.17
SIDS Status	implemented version 4.0
Filemap Status	implemented version 4.0
MLL Status	implemented version 4.0

CPEX0040

CPEX#	0040
Scope	Rind Plane Indexing
Contacts	Stephen Guzik
Documentation	rind_plane_indexing_5_14_2015.pdf
Date First Posted	May.05.14
Date of Last Revision	May.14.15
SIDS Status	implemented version 3.4
Filemap Status	no change required
MLL Status	implemented version 3.4

CPEX0039

CPEX#	0039
Scope	Inter-Base Reference Extension
Contacts	Marc Poinot
Documentation	CGNS-0039-Inter-Base-References1.pdf
Date First Posted	Jan.07.14
Date of Last Revision	Jan.10.14
SIDS Status	implemented version 3.3
Filemap Status	no change required
MLL Status	implemented version 3.3

CPEX0038

CPEX#	0038
Scope	Quartic Elements for High Order
Contacts	Meilin Yu and Z. J. Wang
Documentation	CGNS_P4_elem_defn2.pdf
Date First Posted	Aug.08.13
Date of Last Revision	Sep.10.13
SIDS Status	implemented version 3.3
Filemap Status	no change required
MLL Status	implemented version 3.3

CPEX0037

CPEX#	0037
Scope	Improvements for Multiblock Unstructured
Contacts	Micah Howard and Srini Arunajatesan
Documentation	README.improv_mblk_uns.txt CGNS-MultiBlockUnst.pdf bump_3df_unstr_native_pw.cgns bump_3df_unstr.cgns bump_3df_hybrid.cgns
Date First Posted	May.05.00
Date of Last Revision	Sep.15.00
SIDS Status	current version not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0036

CPEX#	0036
Scope	Cubic Elements for High Order
Contacts	Meilin Yu and Z. J. Wang
Documentation	CGNS_extended_elem_defn2.pdf
Date First Posted	Nov.05.12
Date of Last Revision	Nov.13.12
SIDS Status	implemented version 3.2
Filemap Status	no changed required
MLL Status	implemented version 3.2

CPEX0035

CPEX#	0035
Scope	Rigid Motion in a Family (requires CPEX #0034)
Contacts	Marc Poinot
Documentation	CGNS-prop-ext-FamilyRigidMotion-5.pdf
Date First Posted	Feb.07.11
Date of Last Revision	Feb.07.11
SIDS Status	Current version not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0034

CPEX#	0034
Scope	Multiple Families
Contacts	Marc Poinot
Documentation	CGNS-0034-6.pdf (Note: AdditionalFamilyName also to be added under UserDefinedData)
Date First Posted	Feb.03.11
Date of Last Revision	Nov.16.11
SIDS Status	implemented version 3.2
Filemap Status	implemented version 3.2
MLL Status	implemented version 3.2

CPEX0033

CPEX#	0033
Scope	Hierarchy of Families
Contacts	Marc Poinot
Documentation	CGNS-0033-6.pdf
Date First Posted	Feb.03.11
Date of Last Revision	Nov.16.11
SIDS Status	implemented version 3.2
Filemap Status	implemented version 3.2
MLL Status	implemented version 3.2

CPEX0032

CPEX#	0032
Scope	Rigid Motion Improvement
Contacts	Marc Poinot
Documentation	IterativeData.pdf FrameReference.pdf FamilyRigidMotion.pdf RigidMotion.pdf
Date First Posted	Jul.01.08
Date of Last Revision	Oct.07.08
SIDS Status	withdrawn
Filemap Status	N/A
MLL Status	N/A

CPEX0031

CPEX#	0031
Scope	General SIDS Improvement
Contacts	Steven Allmaras
Documentation	intro_parts_of_sids.pdf parts_of_sids.pdf
Date First Posted	Jun.09.08
Date of Last Revision	Jun.09.08
SIDS Status	implemented version 3.1.3
Filemap Status	implemented version 3.1.3
MLL Status	implemented version 3.1.3

CPEX0030

CPEX#	0030
Scope	Regions
Contacts	Chris Rumsey, Marc Poinot, Bob Bush, Mark Fisher, Steven Allmaras
Documentation	Regions.pdf Regions_filemap.pdf
Date First Posted	Nov.09.06
Date of Last Revision	May.29.11
SIDS Status	implemented version 3.1.3
Filemap Status	implemented version 3.1.3
MLL Status	implemented version 3.1.3

CPEX0029

CPEX#	0029
Scope	Interface Connectivity
Contacts	Chris Rumsey
Documentation	InterpolantDonor.pdf
Date First Posted	Apr.13.07
Date of Last Revision	May.22.07
SIDS Status	implemented version 2.5
Filemap Status	implemented version 2.5
MLL Status	implemented version 2.5

CPEX0028

CPEX#	0028
Scope	Face-Based Storage
Contacts	Steve Allmaras
Documentation	FacebasedIntro.pdf FacebasedSIDS.pdf
Date First Posted	Nov.09.06
Date of Last Revision	Nov.09.06
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0027

CPEX#	0027
Scope	Multiple Zone Connectivities for Time-Dependent
Contacts	Christopher Rumsey, Robert Bush
Documentation	Timedepconn.pdf Timedepconn_filemap.pdf
Date First Posted	Mar.08.06
Date of Last Revision	Mar.08.06
SIDS Status	implemented version 3.1.3
Filemap Status	implemented version 3.1.3
MLL Status	implemented version 3.1.3

CPEX0026

CPEX#	0026
Scope	Face Center Connectivity
Contacts	Laurent de Vito
Documentation	Facecenter.pdf
Date First Posted	Mar.08.06
Date of Last Revision	Mar.08.06
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0025

CPEX#	0025
Scope	Averaging Interfaces
Contacts	Robert Magnan
Documentation	AveragingInterfaces.pdf
Date First Posted	Mar.28.06
Date of Last Revision	Mar.28.06
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0024

CPEX#	0024
Scope	FSI with Deformable Boundaries
Contacts	Daniel Einstein
Documentation	FSIDeformableBdy.pdf
Date First Posted	Dec.17.03
Date of Last Revision	Dec.17.03
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0023

CPEX#	0023
Scope	Rind Data for Unstructured Zones
Contacts	Robert A. Fiedler
Documentation	UnstructuredRind.pdf
Date First Posted	Dec.15.03
Date of Last Revision	Dec.15.03
SIDS Status	implemented version 2.4.3
Filemap Status	implemented version 2.4.3
MLL Status	implemented version 2.4.3

CPEX0022

CPEX#	0022
Scope	Partial Connectivity Read/Write
Contacts	Edwin van der Weide
Documentation	PartialConn.pdf
Date First Posted	Sep.25.03
Date of Last Revision	Sep.25.03
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0021

CPEX#	0021
Scope	Connectivity Property
Contacts	Edwin van der Weide
Documentation	GridConnectivityProperty.pdf
Date First Posted	Sep.25.03
Date of Last Revision	Sep.25.03
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0020

CPEX#	0020
Scope	FamilyBC Extension
Contacts	Edwin van der Weide
Documentation	FamilyBCExtension.pdf
Date First Posted	Apr.21.03
Date of Last Revision	Apr.21.03
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0019

CPEX#	0019
Scope	UserDefined data Extension
Contacts	Robert Bush
Documentation	UserDefinedExtensions.pdf
Date First Posted	Apr.21.03
Date of Last Revision	Apr.21.03
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0018

CPEX#	0018
Scope	BCDataSet Extension
Contacts	Robert Bush
Documentation	BCDataSetExtensions.pdf
Date First Posted	May.05.00
Date of Last Revision	Sep.15.00
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0017

CPEX#	0017
Scope	Chemical Species
Contacts	Robert Bush
Documentation	ChemicalSpecies.pdf
Date First Posted	Oct.25.02
Date of Last Revision	Oct.25.02
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0016

CPEX#	0016
Scope	Element Regions
Contacts	Robert Bush
Documentation	ElementRegions.pdf
Date First Posted	Oct.25.02
Date of Last Revision	Oct.25.02
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0015

CPEX#	0015
Scope	Elemental Components
Contacts	Robert Bush
Documentation	ElementalComponents.pdf
Date First Posted	Oct.25.02
Date of Last Revision	Oct.25.02
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0014

CPEX#	0014
Scope	Boundary Type Extensions
Contacts	Robert Bush
Documentation	BCTypeExtensions.pdf
Date First Posted	Oct.25.02
Date of Last Revision	Oct.25.02
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0013

CPEX#	0013
Scope	Solution BC proposal
Contacts	Robert Bush
Documentation	SolutionBCproposal.pdf
Date First Posted	Jul.03.02
Date of Last Revision	Jul.03.02
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0012

CPEX#	0012
Scope	Electromagnetic proposal
Contacts	Robert Bush
Documentation	EMproposals.pdf
Date First Posted	Jul.03.02
Date of Last Revision	Jul.03.02
SIDS Status	implemented version 2.4
Filemap Status	implemented version 2.4
MLL Status	implemented version 2.4

CPEX0011

CPEX#	0011
Scope	Wall Function, Periodic, Rotor/Stator
Contacts	Robert Bush
Documentation	WallPeriodicRS.pdf
Date First Posted	Jul.01.02
Date of Last Revision	Jul.31.02
SIDS Status	implemented version 2.2
Filemap Status	implemented version 2.2
MLL Status	implemented version 2.2

CPEX0010

CPEX#	0010
Scope	Multi-Phase / Liquid Spray
Contacts	Robert Bush
Documentation	MultiPhaseExtension.pdf
Date First Posted	Dec.01.00
Date of Last Revision	Dec.14.00
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0009

CPEX#	0009
Scope	User Defined Data Arrays
Contacts	Robert Bush
Documentation	UserDefinedDataArrays2.pdf
Date First Posted	Nov.15.00
Date of Last Revision	Feb.02.01
SIDS Status	implemented version 2.1
Filemap Status	implemented version 2.1
MLL Status	implemented version 2.1

CPEX0008

CPEX#	0008
Scope	Hierarchical Elements
Contacts	Michel Delanaye, Etienne Robin, Alpesh Patel
Documentation	HierarchicalElements.pdf , Response from M.Aftosmis: hierarchicalResponse.pdf
Date First Posted	Aug.02.00
Date of Last Revision	Dec.01.00
SIDS Status	not accepted
Filemap Status	N/A
MLL Status	N/A

CPEX0007

CPEX#	0007
Scope	Gravity
Contacts	Robert Bush
Documentation	Gravity.pdf
Date First Posted	Aug.04.99
Date of Last Revision	Mar.15.00
SIDS Status	implemented version 2.2
Filemap Status	implemented version 2.2
MLL Status	implemented version 2.2

CPEX0006

CPEX#	0006
Scope	Rotating Coordinates
Contacts	Robert Bush
Documentation	RotatingCoordinates.pdf
Date First Posted	Aug.04.99
Date of Last Revision	Dec.09.99
SIDS Status	implemented version 2.2
Filemap Status	implemented version 2.2
MLL Status	implemented version 2.2

CPEX0005

CPEX#	0005
Scope	Axisymmetry for 2D grids
Contacts	Robert Bush
Documentation	axisymmetry.pdf
Date First Posted	Aug.04.99
Date of Last Revision	Mar.15.00
SIDS Status	implemented version 2.2
Filemap Status	implemented version 2.2
MLL Status	implemented version 2.2

CPEX0004

CPEX#	0004
Scope	Chemical Species
Contacts	Robert Bush
Documentation	Chemistry.pdf
Date First Posted	Aug.04.99
Date of Last Revision	Sep.15.00
SIDS Status	implemented
Filemap Status	implemented
MLL Status	implemented

CPEX0003

CPEX#	0003
Scope	Iterative or Time-accurate data
Contacts	Christopher Rumsey, Robert Bush, Mark Fisher
Documentation	IterativeOrTemp.pdf
Date First Posted	Aug.04.99
Date of Last Revision	Mar.14.00
SIDS Status	implemented
Filemap Status	implemented
MLL Status	implemented

CPEX0002

CPEX#	0002
Scope	Point by Point Grid Motion
Contacts	Robert Bush
Documentation	ArbitraryGridMotion.pdf , see example 1
Date First Posted	Aug.04.99
Date of Last Revision	Mar.14.00
SIDS Status	implemented
Filemap Status	implemented
MLL Status	implemented

CPEX0001

CPEX#	0001
Scope	Rigid Body Grid Motion
Contacts	Robert Bush
Documentation	RigidGridMotion.pdf , see example 1
Date First Posted	Aug.04.99
Date of Last Revision	Mar.14.00
SIDS Status	implemented
Filemap Status	implemented
MLL Status	implemented