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.

A CPEX issue should be created as a GitHub issue, to track review and CPEX evolution. It is also recommended to create a discussion topic for CPEX at the CGNSTalk Github Discussion Group.

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 submitted either to the CGNSTalk Github Discussion Group or directly in the comment section of the corresponding GitHub 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

CPEX

Contents

CPEX#

CPEX0046#

CPEX0045#

CPEX0044#

CPEX0043#

CPEX0042#

CPEX0041#

CPEX0040#

CPEX0039#

CPEX0038#

CPEX0037#

CPEX0036#

CPEX0035#

CPEX0034#

CPEX0033#

CPEX0032#

CPEX0031#

CPEX0030#

CPEX0029#

CPEX0028#

CPEX0027#

CPEX0026#

CPEX0025#

CPEX0024#

CPEX0023#

CPEX0022#

CPEX0021#

CPEX0020#

CPEX0019#

CPEX0018#

CPEX0017#

CPEX0016#

CPEX0015#

CPEX0014#

CPEX0013#

CPEX0012#

CPEX0011#

CPEX0010#

CPEX0009#

CPEX0008#

CPEX0007#

CPEX0006#

CPEX0005#

CPEX0004#

CPEX0003#

CPEX0002#

CPEX0001#