1、 Recommended Practice AIAA R-101A-2005 The CFD General Notation System Standard Interface Data Structures Downloaded by AIAA on March 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 AIAA R-101A-2005 Recommended Practice The CFD General Notation System Standard Interface Data Structures Maintai
2、ned by The CGNS Steering Sub-committee of the AIAA CFD Committee on Standards Abstract The CFD General Notation System (CGNS) is a standard for recording and recovering computer data associated with the numerical solution of the equations of fluid dynamics. The intent is to facilitate the exchange o
3、f CFD data between sites, between applications codes, and across computing platforms, and to stabilize the archiving of CFD data. The CGNS system consists of a collection of conventions, and software implementing those conventions, for the storage and retrieval of CFD data. It consists of two parts:
4、 (1) a standard format for recording the data, and (2) software that reads, writes, and modifies data in that format. The format is a conceptual entity established by the documentation; the software is a physical product supplied to enable developers to access and produce data recorded in that forma
5、t. The standard format, or paper convention, part of CGNS consists of two fundamental pieces. The first, known as the Standard Interface Data Structures, is described in this Recommended Practice. It defines the intellectual content of the information to be stored. The second, known as the File Mapp
6、ing, defines the exact location in a CGNS file where the data is to be stored. Downloaded by AIAA on March 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 AIAA R-101A-2005 ii Published by American Institute of Aeronautics and Astronautics 1801 Alexander Bell Drive, Reston, VA 20191 Copyright 2
7、007 American Institute of Aeronautics and Astronautics All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America. Downloaded by AIAA on Mar
8、ch 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 ContentsForeword vii1 Introduction 11.1 Major Differences from Previous CGNS Versions . . . . . . . . . . . . . . . . . . . . . . 21.1.1 Version 2.0, Beta 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.1.2 Version 2.0,
9、Beta 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.1.3 Version 2.1, Beta 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.1.4 Version 2.2, Beta 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.1.5 Version 2.3 . . . . . . . . . . .
10、. . . . . . . . . . . . . . . . . . . . . . . . . . 41.1.6 Version 2.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Design Philosophy of Standard Interface Data Structures 63 Conventions 93.1 Data Structure Notation Conventions . . . . . . . . . . . . . . . . . . . .
11、. . . . . . . 93.2 Structured Grid Notation and Indexing Conventions . . . . . . . . . . . . . . . . . . . . 133.3 Unstructured Grid Element Numbering Conventions . . . . . . . . . . . . . . . . . . . . 143.3.1 1-D (Line) Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
12、.3.2 2-D (Surface) Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.3.2.1 Triangular Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.3.2.2 Quadrilateral Elements . . . . . . . . . . . . . . . . . . . . . . . . . . 173.3.3 3-D (Volume) Elements . . . . . .
13、 . . . . . . . . . . . . . . . . . . . . . . . . . 173.3.3.1 Tetrahedral Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.3.3.2 Pyramid Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.3.3.3 Pentahedral Elements . . . . . . . . . . . . . . . . . . . . . . . . .
14、. . 203.3.3.4 Hexahedral Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.3.4 Unstructured Grid Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.4 Multizone Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Building-Block
15、Structure Definitions 274.1 Definition: DataClass_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.2 Definition: Descriptor_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.3 Definition: DimensionalUnits_t . . . . . . . . . . . . . . . . . . . . . . .
16、. . . . . . 284.4 Definition: DimensionalExponents_t . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.5 Definition: GridLocation_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.6 Definition: IndexArray_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 304.7 Definition: IndexRange_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.8 Definition: Rind_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Data-Array Structure Definitions 325.1 Definition: DataArray_t . . . . . . . . . . . . . . . . . .
18、. . . . . . . . . . . . . . . . 325.1.1 Definition: DataConversion_t . . . . . . . . . . . . . . . . . . . . . . . . . . . 335.2 Data Manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345.2.1 Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . 34iiiDownloaded by AIAA on March 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 AIAA R-101A-20055.2.2 Nondimensional Data Normalized by Dimensional Quantities . . . . . . . . . . . 355.2.3 Nondimensional Data Normalized by Unknown Dimensional Quantities . . . . . . 355.2.4 Non
20、dimensional Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385.2.5 Dimensionless Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.3 Data-Array Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 Hierarchical Structures 4
21、46.1 CGNS Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446.2 CGNS Entry Level Structure Definition: CGNSBase_t . . . . . . . . . . . . . . . . . . . 446.3 Zone Structure Definition: Zone_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476.4 Prec
22、edence Rules and Scope Within the Hierarchy . . . . . . . . . . . . . . . . . . . . . 517 Grid Coordinates, Elements, and Flow Solutions 537.1 Grid Coordinates Structure Definition: GridCoordinates_t . . . . . . . . . . . . . . . 537.2 Grid Coordinates Examples . . . . . . . . . . . . . . . . . . .
23、. . . . . . . . . . . . . . 557.3 Elements Structure Definition: Elements_t . . . . . . . . . . . . . . . . . . . . . . . . 587.4 Elements Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 607.5 Axisymmetry Structure Definition: Axisymmetry_t . . . . . . . . . . . .
24、. . . . . . . . 617.6 Rotating Coordinates Structure Definition: RotatingCoordinates_t . . . . . . . . . . 637.7 Flow Solution Structure Definition: FlowSolution_t . . . . . . . . . . . . . . . . . . . 647.8 Flow Solution Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25、668 Multizone Interface Connectivity 698.1 Zonal Connectivity Structure Definition: ZoneGridConnectivity_t . . . . . . . . . . . 698.2 1-to-1 Interface Connectivity Structure Definition: GridConnectivity1to1_t . . . . . 708.3 1-to-1 Interface Connectivity Examples . . . . . . . . . . . . . . . . . .
26、 . . . . . . . . . 738.4 General Interface Connectivity Structure Definition: GridConnectivity_t . . . . . . . 758.5 Grid Connectivity Property Structure Definition: GridConnectivityProperty_t . . . . 788.5.1 Periodic Interface Structure Definition: Periodic_t . . . . . . . . . . . . . . . 798.5.2 A
27、verage Interface Structure Definition: AverageInterface_t . . . . . . . . . . 808.6 Overset Grid Holes Structure Definition: OversetHoles_t . . . . . . . . . . . . . . . . 819 Boundary Conditions 839.1 Boundary Condition Structures Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 849.2 Z
28、onal Boundary Condition Structure Definition: ZoneBC_t . . . . . . . . . . . . . . . . 859.3 Boundary Condition Structure Definition: BC_t . . . . . . . . . . . . . . . . . . . . . . 869.4 Boundary Condition Data Set Structure Definition: BCDataSet_t . . . . . . . . . . . . 909.5 Boundary Condition
29、Data Structure Definition: BCData_t . . . . . . . . . . . . . . . . 929.6 Boundary Condition Property Structure Definition: BCProperty_t . . . . . . . . . . . . 939.6.1 Wall Function Structure Definition: WallFunction_t . . . . . . . . . . . . . . . 949.6.2 Area Structure Definition: Area_t . . . .
30、. . . . . . . . . . . . . . . . . . . . . 959.7 Boundary Condition Type Structure Definition: BCType_t . . . . . . . . . . . . . . . . 969.8 Matching Boundary Condition Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . . 999.9 Boundary Condition Specification Data . . . . . . . . . . . . .
31、 . . . . . . . . . . . . . . 1019.10 Boundary Condition Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103ivDownloaded by AIAA on March 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 AIAA R-101A-200510 Governing Flow Equations 11210.1 Flow Equation Set Structure Defini
32、tion: FlowEquationSet_t . . . . . . . . . . . . . . 11210.2 Governing Equations Structure Definition: GoverningEquations_t . . . . . . . . . . . 11310.3 Thermodynamic Gas Model Structure Definition: GasModel_t . . . . . . . . . . . . . . 11510.4 Molecular Viscosity Model Structure Definition: Viscos
33、ityModel_t . . . . . . . . . . . 11610.5 Thermal Conductivity Model Structure Definition: ThermalConductivityModel_t . . . 11810.6 Turbulence Structure Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11910.6.1 Turbulence Closure Structure Definition: TurbulenceClosure_t . . .
34、 . . . . . 12010.6.2 Turbulence Model Structure Definition: TurbulenceModel_t . . . . . . . . . . 12110.7 Thermal Relaxation Model Structure Definition: ThermalRelaxationModelType_t . . 12410.8 Chemical Kinetics Structure Definition: ChemicalKineticsModel_t . . . . . . . . . . . 12510.9 Electromagne
35、tics Structure Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 12710.9.1 Electromagnetics Electric Field Model Structure Definition: EMElectricField-Model_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12710.9.2 Electromagnetics Magnetic Field Model
36、 Structure Definition: EMMagneticField-Model_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12810.9.3 Electromagnetics Conductivity Model Structure Definition: EMConductivity-Model_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12910.
37、10Flow Equation Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13011 Time-Dependent Flow 13311.1 Iterative Data Structure Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13311.1.1 Base Iterative Data Structure Definition: BaseIterativeData_t . . .
38、. . . . . 13311.1.2 Zone Iterative Data Structure Definition: ZoneIterativeData_t . . . . . . . . 13411.2 Rigid Grid Motion Structure Definition: RigidGridMotion_t . . . . . . . . . . . . . . 13511.3 Arbitrary Grid Motion Structure Definition: ArbitraryGridMotion_t . . . . . . . . . . 13711.4 Exampl
39、es for Time-Dependent Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14012 Miscellaneous Data Structures 14612.1 Reference State Structure Definition: ReferenceState_t . . . . . . . . . . . . . . . . 14612.2 Reference State Example . . . . . . . . . . . . . . . . . . . . . . . . . . .
40、. . . . . . . 14712.3 Convergence History Structure Definition: ConvergenceHistory_t . . . . . . . . . . . 14812.4 Discrete Data Structure Definition: DiscreteData_t . . . . . . . . . . . . . . . . . . . 15012.5 Integral Data Structure Definition: IntegralData_t . . . . . . . . . . . . . . . . . . .
41、 15112.6 Family Data Structure Definition: Family_t . . . . . . . . . . . . . . . . . . . . . . . . 15212.7 Geometry Reference Structure Definition: GeometryReference_t . . . . . . . . . . . . 15312.8 Family Boundary Condition Structure Definition: FamilyBC_t . . . . . . . . . . . . . . 15412.9 User
42、-Defined Data Structure Definition: UserDefinedData_t . . . . . . . . . . . . . . 15512.10Gravity Data Structure Definition: Gravity_t . . . . . . . . . . . . . . . . . . . . . . . 156Annex A. Conventions for Data-Name Identifiers 159A.1 Coordinate Systems . . . . . . . . . . . . . . . . . . . . . .
43、 . . . . . . . . . . . . . . . 159A.2 Flowfield Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160A.3 Turbulence Model Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168A.4 Nondimensional Parameters . . . . . . . . . . . . . . . . . .
44、 . . . . . . . . . . . . . . . 168vDownloaded by AIAA on March 27, 2014 | http:/arc.aiaa.org | DOI: 10.2514/4.479304 A.5 Characteristics and Riemann Invariants Based on 1-D Flow . . . . . . . . . . . . . . . . 170A.6 Forces and Moments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45、. . . . . 170A.7 Time-Dependent Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173Annex B. Structured Two-Zone Flat Plate Example 175B.1 Overall Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176B.2 Grid Coordinates . . . . . . .
46、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177B.3 Flowfield Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178B.4 Interface Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180B.5 Boundary Conditions . . .
47、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183B.6 Global Reference State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186B.7 Equation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188List of Figures1 Sample
48、Topologically Based CFD Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . 72 Structured-Grid Multizone Interface Types . . . . . . . . . . . . . . . . . . . . . . . . . 253 Example Interface for 1-to-1 Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . 744 Hierarchy for Boundary
49、Condition Structures . . . . . . . . . . . . . . . . . . . . . . . . 855 Boundary Condition Implementation Levels . . . . . . . . . . . . . . . . . . . . . . . . 1036 Two-Zone Flat Plate Test Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175List of Tables1 Element Types in CGNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Simple Boundary Condition Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 973 Compound Boundary Condition Types . . . . . . . . . . . . . . . . . . . . . . . . . . . 994 Associated Boundary Conditio
