1、GuideAIAAG-077-1998(2002)Guide for the Verification andValidation of ComputationalFluid Dynamics SimulationsAIAA standards are copyrighted by the American Institute of Aeronautics andAstronautics (AIAA), 1801 Alexander Bell Drive, Reston, VA 20191-4344 USA. All rightsreserved.AIAA grants you a licen
2、se as follows: The right to download an electronic file of this AIAAstandard for temporary storage on one computer for purposes of viewing, and/or printingone copy of the AIAA standard for individual use. Neither the electronic file nor the hardcopy print may be reproduced in any way. In addition, t
3、he electronic file may not bedistributed elsewhere over computer networks or otherwise. The hard copy print may onlybe distributed to other employees for their internal use within your organization.AIAAG-077-1998GuideGuide for the Verification and Validationof Computational Fluid Dynamics Simulation
4、sSponsorAmerican Institute of Aeronautics and AstronauticsApproved January 14, 1998Reaffirmed June 25, 2002AbstractThis document presents guidelines for assessing the credibility of modeling and simulation incomputational fluid dynamics. The two main principles that are necessary for assessing credi
5、bilityare verification and validation. Verification is the process of determining if a computationalsimulation accurately represents the conceptual model, but no claim is made of the relationship ofthe simulation to the real world. Validation is the process of determining if a computationalsimulatio
6、n represents the real world. This document defines a number of key terms, discussesfundamental concepts, and specifies general procedures for conducting verification and validationof computational fluid dynamics simulations. The documents goal is to provide a foundation forthe major issues and conce
7、pts in verification and validation. However, this document does notrecommend standards in these areas because a number of important issues are not yet resolved.It is hoped that the guidelines will aid in the research, development, and use of computationalfluid dynamics simulations by establishing co
8、mmon terminology and methodology for verificationand validation. The terminology and methodology should also be useful in other engineering andscience disciplines.AIAA G-077-1998Library of Congress Cataloging-in-Publication DataAIAA guide for the verification and validation of computational fluid dy
9、namics simulations / sponsor, American Institute of Aeronautics and Astronautics. p. cm.Includes bibliographical references.ISBN 1-56347-285-61.Fluid dynamics-Computer simulation-Evaluation. 2. Fluiddynamics-Mathematical models-Evaluation. I. American Instituteof Aeronautics and Astronautics.QA911.A
10、54 1998620.10640113-dc21 98-8138CIPPublished byAmerican Institute of Aeronautics and Astronautics1801 Alexander Bell Drive, Suite 500, Reston, VA 20191-4344Copyright 1998 American Institute of Aeronautics and AstronauticsAll rights reserved.No part of this publication may be reproduced in any form,
11、in an electronic retrieval system or otherwise,without prior written permission of the publisher.Printed in the United States of America.iiAIAA G-077-1998Table of ContentsForeword vExecutive Summary. vii1 . Introduction. 11.1 Background. 11.2 Scope. 11.3 Outline 22 . Concepts and Terminology. 22.1 M
12、odeling and Simulation.22.2 Verification and Validation.32.3 Uncertainty and Error42.4 Prediction and Levels of Credibility 53 . Verification Assessment. 73.1 Grid and Time-Step Convergence. 73.2 Iterative Convergence and Consistency Tests. 83.3 Highly Accurate Solutions 94 . Validation Assessment.1
13、04.1 Validation Phases.114.2 Calibration134.3 Requirements for Experimental Data145 . Summary and Conclusions 146 . References 15iiiAIAA G-077-1998List of FiguresFigure 1 Phases of Modeling and Simulation 3Figure 2 Verification Process. 7Figure 3 Validation Process10Figure 4 Validation Phases.11Figu
14、re 5 Characteristics of Validation Phases.11Figure 6 Use of Completed Validation Cases for New Applications 12ivAIAA G-077-1998ForewordThe American Institute of Aeronautics and Astronautics (AIAA) Standards Program sponsoreddevelopment of this document, Guide for the Verification and Validation of C
15、omputational Fluid DynamicsSimulations. This document originated within the AIAA Computational Fluid Dynamics Committee onStandards, which is composed of AIAA members and others who are not affiliated with AIAA. Committeemembers come from industry, government, and academia, and serve voluntarily wit
16、hout compensation.This document represents a consensus of the Committees opinions on the terminology andmethodology for verification and validation of computational fluid dynamics (CFD) simulations.This document is primarily a synthesis of opinions from the published literature on verification andva
17、lidation in modeling and simulation. Perspectives from a wide variety of sources were assembled inorder to develop the most useful, self-consistent, and logical framework. Even though there is a variety ofopinion on verification and validation in the literature, there is increasing agreement on the
18、fundamentalaspects. It is hoped that this document will promote consensus on the major issues among the CFDcommunity at large.The goal of this document is to support researchers, developers, and users of CFD by establishingcommon terminology and methodology for verification and validation of CFD sim
19、ulations. The terminologyand methodology should also be useful in other engineering and science disciplines.The AIAA Standards Procedures provides that all approved guides, recommended practices, andstandards are advisory only. The use of these publications by anyone engaged in industry or trade ise
20、ntirely voluntary. There is no agreement to adhere to any AIAA standards publication and no commitmentto conform to or be guided by any standards report. This guide is not intended to be used for certificationor accreditation of codes. In formulating, revising, and approving standards publications,
21、the AIAACommittees on Standards will not consider patents that may apply to the subject matter. Prospectiveusers of the publications are responsible for protecting themselves against liability for infringement ofpatents, or copyrights, or both.This document is subject to change based on developments
22、 in the state of the art and on commentsreceived from readers. Comments are welcome from any interested party, regardless of membershipaffiliation with AIAA. Comments should be directed to:American Institute of Aeronautics and AstronauticsStandards Department1801 Alexander Bell Drive, Suite 500Resto
23、n, VA 22091or, by electronic mail to:standardsaiaa.orgThe first draft of this guide was prepared by Unmeel B. Mehta. This draft was prepared by William L.Oberkampf, Munir M. Sindir, and A. Terrence Conlisk. A number of comments and suggestions forimprovements of the document were made by members of
24、the AIAA Computational Fluid DynamicsCommittee on Standards and by several interested individuals who were not on the Committee. Weappreciate and value all input provided.The following committee members voted on this document:John L. Porter, Committee Chair (Sverdrup Technology)Ramesh Agarwal (Wichi
25、ta State University)vAIAA G-077-1998Ram S. Azad (University of Manitoba)Donald Bain (CFD Research Corporation)John A. Benek (Microcraft Corporation)Bobby L. Berrier (NASA Langley Research Center)A. Terrence Conlisk (Ohio State University)Raymond R. Cosner (The Boeing Company)Robert A. Delaney (Allis
26、on Engine Company)Klaus Hoffmann (Wichita State University)Michael S. Holden (Calspan Corporation)Louis G. Hunter (Lockheed Martin Corporation)Yuji Ikeda (Kobe University)R. E. Luxton (University of Adelaide)Joseph G. Marvin (NASA Ames Research Center)Unmeel B. Mehta (NASA Ames Research Center)Rober
27、t E. Melnik (Northrop Grumman Corporation)Michele Napolitano (Politechnico Di Bari)William L. Oberkampf (Sandia National Laboratories)Gerald A. Paynter (The Boeing Company)Louis A. Povinelli (NASA Lewis Research Center)Cary Presser (National Institute of Standards and Technology)Balu Sekar (U.S. Air
28、 Force Wright Laboratory)Munir M. Sindir (The Boeing Company)Ashok K. Singhal (CFD Research Corporation)Ambady Suresh (NYMA, Inc.)John C. Tannehill (Iowa State University)The CFD Committee on Standards approved the document on January 14, 1998. The AIAAStandards Executive Council accepted it for pub
29、lication on May 6, 1998.viAIAA G-077-1998Executive SummaryComputer simulations of fluid flow processes are now used to design, investigate, and operateengineered systems and to determine the performance of these systems under various conditions.Computational fluid dynamics (CFD) simulations are also
30、 used to improve understanding of fluid physicsand chemistry, such as turbulence and combustion, and to aid in weather prediction and oceanography.Although CFD simulations are widely conducted in industry, government, and academia, there ispresently little agreement on procedures for assessing their
31、 credibility. These guidelines are predicatedupon the notion that there is no fixed level of credibility or accuracy that is applicable to all CFD simulations.The accuracy level required of simulations depends on the purposes for which the simulations are to beused. The two main principles that are
32、necessary for establishing credibility are verification and validation(V and 2) within each time step for initial-boundary valueproblems. In verification testing, the sensitivity of the solution to the magnitude of the convergencecriteria should be varied, and a value should be established that is c
33、onsistent with the objectives of thesimulation. In verification activities, comparing a computational solution to a highly accurate solution is themost accurate and reliable way to quantitatively measure the error in the computational solution. However,highly accurate solutions are known only for a
34、relatively small number of simplified problems. These highlyaccurate solutions can be classified into three types: analytical solutions, benchmark numerical solutionsto ordinary differential equations (ODEs), and benchmark numerical solutions to partial differentialequations (PDEs). As one moves fro
35、m analytical solutions to ODE solutions to PDE solutions, theaccuracy of the benchmark solutions clearly becomes more of an issue.The fundamental strategy of validation is the identification and quantification of error and uncertainty inthe conceptual and computational models. The recommended valida
36、tion method is to employ a building-block approach. This approach divides the complex engineering system of interest into threeprogressively simpler phases: subsystem cases, benchmark cases, and unit problems. The strategy in thisapproach is the assessment of how accurately the computational results
37、 compare with experimental data(with quantified uncertainty estimates) at multiple levels of complexity. Each phase of the processrepresents a different level of flow physics coupling and geometrical complexity. The complete systemconsists of the actual hardware or system for which a validated CFD t
38、ool is needed. Thus all the geometricand flow physics effects occur simultaneously; commonly, the complete system includes multidisciplinaryphysical phenomena. Subsystem cases represent the first decomposition of the actual hardware intosimplified or partial flow paths. Each of these cases commonly
39、exhibits restricted geometric or flowfeatures compared to the complete system. Benchmark cases represent another level of successivedecomposition of the complete system. For these cases, separate hardware is fabricated to represent keyfeatures of each subsystem. The benchmark cases are geometrically
40、 simpler than those at the subsystemlevel, as only two separate features of the flow physics and two flow features are commonly coupled in thebenchmark cases. Unit problems represent the total decomposition of the complete system. High-precision, special-purpose hardware is fabricated and inspected.
41、 Unit problems are characterized by verysimple geometries, one flow-physics feature, and one dominant flow feature. Each of these phases is alsocharacterized by different quantities of experimental information available for the initial conditions andboundary conditions that are used to solve the PDE
42、s at each phase. In addition, the estimate ofexperimental measurement uncertainty varies considerably from one phase to another.viiiAIAA G-077-19981. Introduction needed to derive the greatest benefit from CFDmodeling and simulation.1.1 Background1.2 ScopeComputational fluid dynamics (CFD) is anemer
43、ging technology. It is the merger of the classical The fundamental strategy of V but no claim is made of the be made with broad input from other AIAA Technicalrelationship of the simulation to the real world. Committees and any individuals interested in theValidation is the process of determining if
44、 a advancement of CFD.computational simulation represents the real world.Verification determines whether the problem has A few archival journals have developed editorialbeen solved correctly, whereas validation policies pertaining to the control of numericaldetermines whether the correct problem has
45、 been accuracy in fluid flow simulations 5-8. Numericalsolved. A consistent and logical framework for V such simulations only need to be useful, subsections define and discuss a set of key terms fornot perfect. The required level of accuracy must be modeling and simulation in CFD.determined for each
46、 use of the simulation. Typicalpracticalities affecting the accuracy obtained are 2.1 Modeling and Simulationcost, schedule, and safety implications of thesimulation. The terms model, modeling, and simulationare used in a wide range of disciplines.1.3 Outline Consequently, these terms have a range o
47、fmeanings that are both context-specific andSection 2 defines a number of fundamental discipline-specific 16, 20. As used in this guide, theterms, such as model, error, uncertainty, and terms are defined as follows:prediction. The reasoning for choosing thedefinitions and the implications of the def
48、initions are Model: A representation of a physical system oralso discussed. Section 3 describes the process intended to enhance our ability tomethodology for verification, which is applicable to understand, predict, or control its behavior.discretized solutions of the partial differentialequations o
49、f fluid dynamics. The recommended Modeling: The process of construction orprocedures apply to finite difference methods, finite modification of a model.element methods, finite volume methods, spectralmethods, and boundary element methods. The Simulation: The exercise or use of a model. (Thatuses of analytical solutions and benchmark numerical is, a model is used in a simulation.)solutions in verification are presented, along withThe basic phases of modeling and simulationissues related to spatial and time-step convergencehave been identified by the OR community. Figur
