1、Designation: E 1355 05aAn American National StandardStandard Guide forEvaluating the Predictive Capability of Deterministic FireModels1This standard is issued under the fixed designation E 1355; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 f
3、or a 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
4、to be 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
5、firescenarios.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
6、.4 This guide assumes understanding of the use and limi-tations of the model under analysis as detailed in GuideE 1895.1.5 This fire standard cannot be used to provide quantitativemeasures.2. Referenced Documents2.1 ASTM Standards:2E 176 Terminology of Fire StandardsE 603 Guide for Room Fire Experim
7、entsE 1472 Guide for Documenting Computer Software for FireModelsE 1591 Guide for Obtaining Data for Deterministic FireModelsE 1895 Guide for Determining Uses and Limitations ofDeterministic Fire Models2.2 International Standards Organization Standards:Guide to the Expression of Uncertainty in Measu
8、rement33. Terminology3.1 Definitions: For definitions of terms used in this guideand associated with fire issues, refer to terminology containedin Terminology E 176 and ISO 13943. In case of conflict, thedefinitions given in Terminology E 176 shall prevail.3.2 Definitions of Terms Specific to This S
9、tandard:3.2.1 model evaluationthe process of quantifying theaccuracy of chosen results from a model when applied for aspecific use.3.2.2 model validationthe process of determining thedegree to which a calculation method is an accurate represen-tation of the real world from the perspective of the int
10、endeduses of the calculation method.3.2.2.1 DiscussionThe fundamental strategy of validationis the identification and quantification of error and uncertaintyin the conceptual and computational models with respect tointended uses.3.2.3 model verificationthe process of determining thatthe implementati
11、on of a calculation method accurately repre-sents the developers conceptual description of the calculationmethod and the solution to the calculation method.3.2.3.1 DiscussionThe fundamental strategy of verifica-tion of computational models is the identification and quanti-fication of error in the co
12、mputational 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 accuracy refers to how well the model replicatesthe evolution of an actual fire.4. Summary of Guide4.1 A recommended process for evaluating the predictiv
13、ecapability of fire models is described. This process includes a1This 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 April 1, 2005. Published May 2005. Originallyapprove
14、d in 1990. Last previous edition approved in 2005 as E 1355 05.2For 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 Document Summary page onthe ASTM websit
15、e.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.brief description of the model and the scenarios for whichevaluation is sough
16、t. Then, methodologies for conducting ananalysis to quantify the sensitivity of model predictions tovarious uncertain factors are presented, and several alternativesfor evaluating the accuracy of the predictions of the model areprovided. Historically, numerical accuracy has been concernedwith time s
17、tep size and errors. A more complete evaluationmust include spatial discretization. Finally, guidance is givenconcerning the 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
18、uses and limitations of fire models. It isnot possible to evaluate a model in total; instead, this guide isintended to provide 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.
19、 Several alternatives are provided for performing theevaluation process including: comparison of predictionsagainst standard 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 fireres
20、earch laboratory and into the engineering, fire service andlegal communities. Sufficient evaluation of fire models isnecessary 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
21、thelevel of confidence which can be placed on the resultspredicted by the models.Adequate evaluation will help preventthe unintentional misuse of fire models.5.3 This guide assumes understanding of the use and limi-tations of the model under analysis as detailed in E 1895.5.4 This guide is intended
22、to be used in conjunction withother guides under development by Committee E05. It isintended for use by:5.4.1 Model DevelopersTo document the usefulness of aparticular calculation method perhaps for specific applications.Part of model development includes identification of precisionand limits of app
23、licability, and independent testing.5.4.2 Model UsersTo assure themselves that they areusing an appropriate model for an application 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 App
24、roving OffcialsTo ensure that the results ofcalculations using mathematical models stating conformance tothis guide, cited in 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-cept
25、ability of calculation methods being taught.5.5 This guide is not meant to describe an acceptance testingprocedure.5.6 The emphasis 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 accur
26、acy of a model refers to how well the modelreplicates the evolution of an actual fire.6. General Methodology6.1 The methodology 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 th
27、e theoretical basisand assumptions used in the model,6.1.3 Assessing the mathematical and numerical robustnessof the model, and6.1.4 Quantifying the uncertainty and accuracy of the modelresults in predicting the course of events in similar firescenarios.6.2 Model and Scenario Definition:6.2.1 Model
28、DocumentationSufficient documentation ofcalculation models, including computer software, is absolutelynecessary to assess the adequacy of the scientific and technicalbasis of the models, and the accuracy of computationalprocedures. Also, adequate documentation will help preventthe unintentional misu
29、se of fire models. Guidance on thedocumentation of computer-based fire models is provided inGuide E 1472. Guidance on the use and limitations of deter-ministic fire models and on required knowledge is provided inGuide E 1895. Details applicable to evaluation of the predic-tive capability of fire mod
30、els 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 application of the model, toaid in developing realistic inputs for the model, and to developcriteria for judging the results of the
31、 evaluation. Detailsapplicable to evaluation of the predictive capability of firemodels are provided in 7.2.6.3 Theoretical Basis and Assumptions in the ModelAnindependent review of the underlying physics and chemistryinherent in a model ensures appropriate application of submod-els which have been
32、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 RobustnessThe com-puter implementation of the model should be checked to ensuresuch implementation matches the stated documentati
33、on. 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 Quantifying the Uncertainty and Accuracy of the Model:6.5.1 Model UncertaintyEven deterministic models relyon inputs often based o
34、n experimental measurements, empiri-cal correlations, or estimates made by engineering judgment.Uncertainties in the model inputs can lead to correspondinguncertainties in the model outputs. Sensitivity analysis is usedto quantify these uncertainties in the model outputs based uponknown or estimated
35、 uncertainties in model inputs. Guidancefor obtaining input data for fire models is provided by GuideE 1355 05a2E 1591. Details of sensitivity analysis applicable to evaluationof the predictive capability of fire models are provided inSection 10.6.5.2 Experimental UncertaintyIn general, the result o
36、fmeasurement 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 quantitativestatement of uncertainty. Guidance for conducting full-scalecompartment tests is provided by Guide E 603. Guidance for
37、determining the uncertainty in measurements is provided in theISO Guide to the Expression of Uncertainty in Measurement.6.5.3 Model EvaluationObtaining accurate estimates offire behavior using predictive fire models involves insuringcorrect model inputs appropriate to the scenarios to be mod-eled, c
38、orrect 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.Evaluation of a specific scenario with different levels ofknowledge of the expected results of the calculation addressest
39、hese multiple sources of potential error. Details applicable toevaluation of the predictive capability of fire models areprovided in Section 11.7. Model and Scenario Definition7.1 Model DocumentationProvides details of the modelevaluated in sufficient detail such that the user of the evaluationcould
40、 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),7.1.3 A list of relevant publications,7.1.4 A statement of the stated uses, limitations, and resultsof the model,7.1.5 The
41、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 inherent in the model and thegoverning equations included in the model formulation, and7.1.6.2 The numerics employed to solve
42、 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 The input data required to run the model, and7.1.9 Property data that are defined with the computerprogram or were assumed i
43、n 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 equation, and in a CFD model itmight be the free slip/no slip boundary conditions.7.2 Scenarios for which the Model has been E
44、valutatedProvides details on the range of parameters for which theevaluation has been conducted. Sufficient information shouldbe included such that the user of the evaluation could indepen-dently repeat the evalutation. At a minimum, the followinginformation should be provided:7.2.1 A description of
45、 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.8. Theoretical Basis for the Model8.1 The theoretical basis of the model should be subjected toa peer review by one or mo
46、re recognized experts fullyconversant with the chemistry and physics of fire phenomenabut not involved with the production of the model. Publicationof the theoretical basis of the model in a peer-reviewed journalarticle may be sufficient to fulfill this review. This reviewshould include:8.1.1 An ass
47、essment 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 scientificevidence in the open scientific literature to justify the ap-proaches and assumptions being used.8.1.3 An assessment of the a
48、ccuracy 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. Mathem
49、atical and Numerical Robustness9.1 Analyses which can be performed include:9.1.1 Analytical TestsIf the program is to be applied to asituation for which there is a known mathematical solution,analytical testing is a powerful way of testing the correctfunctioning of a model. However, there are relatively fewsituations (especially for complex scenarios) for which analyti-cal solutions are known.Analytic tests for submodels should beperformed. For example, it is possible to provide a closed-formsolution for heat loss through a partition; the model should beable to
