1、Designation: E1355 11An American National StandardStandard Guide forEvaluating the Predictive Capability of Deterministic FireModels1This standard is issued under the fixed designation E1355; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide provides a methodology for evaluating thepredictive capabilities of a fire model for a
3、 specific use. Theintent is to cover the whole range of deterministic numericalmodels which might be used in evaluating the effects of fires inand on structures.1.2 The methodology is presented in terms of four areas ofevaluation:1.2.1 Defining the model and scenarios for which theevaluation is to b
4、e conducted,1.2.2 Verifying the appropriateness of the theoretical basisand assumptions used in the model,1.2.3 Verifying the mathematical and numerical robustnessof the model, and1.2.4 Quantifying the uncertainty and accuracy of the modelresults in predicting of the course of events in similar fire
5、scenarios.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 T
6、his guide assumes understanding of the use and limi-tations of the model under analysis as detailed in Guide E1895.1.5 This fire standard cannot be used to provide quantitativemeasures.2. Referenced Documents2.1 ASTM Standards:2E176 Terminology of Fire StandardsE603 Guide for Room Fire ExperimentsE1
7、472 Guide for Documenting Computer Software for FireModelsE1591 Guide for Obtaining Data for Deterministic FireModelsE1895 Guide for Determining Uses and Limitations ofDeterministic Fire Models2.2 International Standards Organization Standards:3ISO/IEC Guide 98 (2008) Uncertainty of measurement Part
8、 3: Guide to the expression of uncertainty in measure-mentISO 16730 (2008) Fire safety engineering Assessment,verification and validation of calculation methods3. Terminology3.1 Definitions: For definitions of terms used in this guideand associated with fire issues, refer to terminology containedin
9、Terminology E176 and ISO 13943. In case of conflict, thedefinitions given in Terminology E176 shall prevail.3.2 Definitions of Terms Specific to This Standard:3.2.1 model evaluationthe process of quantifying theaccuracy of chosen results from a model when applied for aspecific use.3.2.2 model valida
10、tionthe process of determining thedegree to which a calculation method is an accurate represen-tation of the real world from the perspective of the intendeduses of the calculation method.3.2.2.1 DiscussionThe fundamental strategy of validationis the identification and quantification of error and unc
11、ertaintyin the conceptual and computational models with respect tointended uses.3.2.3 model verificationthe process of determining thatthe implementation of a calculation method accurately repre-sents the developers conceptual description of the calculationmethod and the solution to the calculation
12、method.3.2.3.1 DiscussionThe fundamental strategy of verifica-tion of computational models is the identification and quanti-fication of error in the computational model and its solution.3.2.4 The precision of a model refers to the deterministiccapability of a model and its repeatability.3.2.5 The ac
13、curacy refers to how well the model replicatesthe evolution of an actual fire.1This guide is under the jurisdiction ofASTM Committee E05 on Fire Standardsand is the direct responsibility of Subcommittee E05.33 on Fire Safety Engineering.Current edition approved Jan. 1, 2011. Published January 2011.
14、Originallyapproved in 1990. Last previous edition approved in 2005 as E1355 05a. DOI:10.1520/E1355-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
15、Document Summary page onthe ASTM website.3Available from American National Standards Institute, 11 West 42nd Street,13th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Guide4.1 A recommended p
16、rocess for evaluating the predictivecapability of fire models is described. This process includes abrief description of the model and the scenarios for whichevaluation is sought. Then, methodologies for conducting ananalysis to quantify the sensitivity of model predictions tovarious uncertain factor
17、s are presented, and several alternativesfor evaluating the accuracy of the predictions of the model areprovided. Historically, numerical accuracy has been concernedwith time step size and errors. A more complete evaluationmust include spatial discretization. Finally, guidance is givenconcerning the
18、 relevant documentation required to summarizethe evaluation process.5. Significance and Use5.1 The process of model evaluation is critical to establish-ing both the acceptable uses and limitations of fire models. It isnot possible to evaluate a model in total; instead, this guide isintended to provi
19、de a methodology for evaluating the predic-tive capabilities for a specific use. Validation for one applica-tion or scenario does not imply validation for different sce-narios. Several alternatives are provided for performing theevaluation process including: comparison of predictionsagainst standard
20、 fire tests, full-scale fire experiments, fieldexperience, published literature, or previously evaluated mod-els.5.2 The use of fire models currently extends beyond the fireresearch laboratory and into the engineering, fire service andlegal communities. Sufficient evaluation of fire models isnecessa
21、ry to ensure that those using the models can judge theadequacy of the scientific and technical basis for the models,select models appropriate for a desired use, and understand thelevel of confidence which can be placed on the resultspredicted by the models.Adequate evaluation will help preventthe un
22、intentional misuse of fire models.5.3 This guide assumes understanding of the use and limi-tations of the model under analysis as detailed in E1895.5.4 This guide is intended to be used in conjunction withother guides under development by Committee E05. It isintended for use by:5.4.1 Model Developer
23、sTo document the usefulness of aparticular calculation method perhaps for specific applications.Part of model development includes identification of precisionand limits of applicability, and independent testing.5.4.2 Model UsersTo assure themselves that they areusing an appropriate model for an appl
24、ication and that itprovides adequate accuracy.5.4.3 Developers of Model Performance CodesTo be surethat they are incorporating valid calculation procedures intocodes.5.4.4 Approving OffcialsTo ensure that the results ofcalculations using mathematical models stating conformance tothis guide, cited in
25、 a submission, show clearly that the modelis used within its applicable limits and has an acceptable levelof accuracy.5.4.5 EducatorsTo demonstrate the application and ac-ceptability of calculation methods being taught.5.5 This guide is not meant to describe an acceptance testingprocedure.5.6 The em
26、phasis of this guide is numerical models of fireevolution.5.6.1 The precision of a model refers to the deterministiccapability of a model and its repeatability.5.6.2 The accuracy of a model refers to how well the modelreplicates the evolution of an actual fire.6. General Methodology6.1 The methodolo
27、gy is presented in terms of four areas ofevaluation:6.1.1 Defining the model and scenarios for which theevaluation is to be conducted,6.1.2 Assessing the appropriateness of the theoretical basisand assumptions used in the model,6.1.3 Assessing the mathematical and numerical robustnessof the model, a
28、nd6.1.4 Quantifying the uncertainty and accuracy of the modelresults in predicting the course of events in similar firescenarios.6.1.5 This general methodology is also consistent with themethodology presented in ISO 16730, Fire safety engineering Assessment, verification and validation of calculatio
29、n meth-ods, which is a potentially useful resource which can be usedwith ASTM E1355.6.2 Model and Scenario Definition:6.2.1 Model DocumentationSufficient documentation ofcalculation models, including computer software, is absolutelynecessary to assess the adequacy of the scientific and technicalbasi
30、s of the models, and the accuracy of computationalprocedures. Also, adequate documentation will help preventthe unintentional misuse of fire models. Guidance on thedocumentation of computer-based fire models is provided inGuide E1472. Guidance on the use and limitations of deter-ministic fire models
31、 and on required knowledge is provided inGuide E1895. Details applicable to evaluation of the predictivecapability of fire models are provided in 7.1.6.2.2 Scenario DocumentationProvide a complete de-scription of the scenarios or phenomena of interest in theevaluation to facilitate appropriate appli
32、cation of the model, toaid in developing realistic inputs for the model, and to developcriteria for judging the results of the evaluation. Detailsapplicable to evaluation of the predictive capability of firemodels are provided in 7.2.6.3 Theoretical Basis and Assumptions in the ModelAnindependent re
33、view of the underlying physics and chemistryinherent in a model ensures appropriate application of submod-els which have been combined to produce the overall model.Details applicable to evaluation of the predictive capability offire models are provided in Section 8.6.4 Mathematical and Numerical Rob
34、ustnessThe com-puter implementation of the model should be checked to ensuresuch implementation matches the stated documentation. De-tails applicable to evaluation of the predictive capability of firemodels are provided in Section 9. Along with 6.3, thisconstitutes verification of the model.6.5 Quan
35、tifying the Uncertainty and Accuracy of the Model:E1355 1126.5.1 Model UncertaintyEven deterministic models relyon inputs often based on experimental measurements, empiri-cal correlations, or estimates made by engineering judgment.Uncertainties in the model inputs can lead to correspondinguncertaint
36、ies in the model outputs. Sensitivity analysis is usedto quantify these uncertainties in the model outputs based uponknown or estimated uncertainties in model inputs. Guidancefor obtaining input data for fire models is provided by GuideE1591. Details of sensitivity analysis applicable to evaluationo
37、f the predictive capability of fire models are provided inSection 10.6.5.2 Experimental UncertaintyIn general, the result ofmeasurement is only the result of an approximation or estimateof the specific quantity subject to measurement, and thus theresult is complete only when accompanied by a quantit
38、ativestatement of uncertainty. Guidance for conducting full-scalecompartment tests is provided by Guide E603. Guidance fordetermining the uncertainty in measurements is provided in theISO Guide to the Expression of Uncertainty in Measurement.6.5.3 Model EvaluationObtaining accurate estimates offire
39、behavior using predictive fire models involves insuringcorrect model inputs appropriate to the scenarios to be mod-eled, correct selection of a model appropriate to the scenariosto be modeled, correct calculations by the model chosen, andcorrect interpretation of the results of the model calculation
40、.Evaluation of a specific scenario with different levels ofknowledge of the expected results of the calculation addressesthese multiple sources of potential error. Details applicable toevaluation of the predictive capability of fire models areprovided in Section 11.7. Model and Scenario Definition7.
41、1 Model DocumentationProvides details of the modelevaluated in sufficient detail such that the user of the evaluationcould independently repeat the evaluation. At a minimum, thefollowing information should be provided:7.1.1 The name and version of the model,7.1.2 The name of the model developer(s),7
42、.1.3 A list of relevant publications,7.1.4 A statement of the stated uses, limitations, and resultsof the model,7.1.5 The type of model, that is the general basis in terms offinite element control volume, Lagrangian, etc.,7.1.6 A statement of the modeling rigor, including:7.1.6.1 The assumptions inh
43、erent in the model and thegoverning equations included in the model formulation, and7.1.6.2 The numerics employed to solve the equations andthe method by which individual solutions are coupled.7.1.7 Additional assumptions of the model as they relate tothe stated uses or other potential uses,7.1.8 Th
44、e input data required to run the model, and7.1.9 Property data that are defined with the computerprogram or were assumed in the model development. Thisshould include what empirical information is included and theuncertainty inherent in the choice. An example in zone mod-eling would be the plume equa
45、tion, and in a CFD model itmight be the free slip/no slip boundary conditions.7.2 Scenarios for which the Model has been EvalutatedProvides details on the range of parameters for which theevaluation has been conducted. Sufficient information shouldbe included such that the user of the evaluation cou
46、ld indepen-dently repeat the evalutation. At a minimum, the followinginformation should be provided:7.2.1 A description of the scenarios or phenomena ofinterest,7.2.2 A list of quantities predicted by the model for whichevaluation is sought, and7.2.3 The degree of accuracy required for each quantity
47、.8. Theoretical Basis for the Model8.1 The theoretical basis of the model should be subjected toa peer review by one or more recognized experts fullyconversant with the chemistry and physics of fire phenomenabut not involved with the production of the model. Publicationof the theoretical basis of th
48、e model in a peer-reviewed journalarticle may be sufficient to fulfill this review. This reviewshould include:8.1.1 An assessment of the completeness of the documen-tation particularly with regard to the assumptions and approxi-mations.8.1.2 An assessment of whether there is sufficient scientificevi
49、dence in the open scientific literature to justify the ap-proaches and assumptions being used.8.1.3 An assessment of the accuracy and applicability of theempirical or reference data used for constants and defaultvalues in the context of the model.8.1.4 The set of equations that is being solved; in cases forwhich closure equations are needed (not included in 8.1.3) theassumption and implication of such choices.9. Mathematical and Numerical Robustness9.1 Analyses which can be performed include:9.1.1 Analytical TestsIf the program is to be applied to asituatio
