ASTM_D_2506_-_80_1989_scan.pdf

ASTMD250680II075951000258106IImDesignation:D2506-80(Reapproved1989)Standard Terminology Relating toSolidRocketPropulsion1r-_-.,AnAmericanNationalStandardThisstandardisissuedunder thefixeddesignation D2506;the nlimber immediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicates theyearoflastreapproval.Asuperscriptepsilon(E)indicatesaneditorialchangesince thelastrevisionorreapproval.1.Scope1.1These symbolsanddefinitions provide nomenclaturefor those parametersofcommonusage associated with solidrocket propulsion.Intheinterestofcommonunderstandingandstandardization,consistent word usage is encouragedtohelp eliminatethemajor barriertoeffective technical com-munication,particularlyinthe caseofwords having eco-nomic importance.2.Significance and Use2.1Significant terms are grouped into major categorieswhich have generally accepted meanings.Within each majorcategory,significant termsaregiven definite meanings,symbols,anddefinitions.Thefollowingcriteria determineacceptabilityofa term for inclusion:2.1.1Theterm isofinteresttosolid propulsion workers.2.1.2Thetermhas a specific applicationorhas beensubject to misunderstandingormisuse.2.1.3Theterm isnotadequately defined for general useinany standard dictionary.2.1.4 Terms are usedincurrent systems.DEFINfI10NORDESCRIPTION OF TERMS3.Geometry-Lineardimensions shallbeexpressedinfeetorinche&,includinganydecimal parts,andabbreviatedasftorin.Angular dimensions shallbeexpressedindegreesanddecimal partsofa degree,for example,15.23 deg.3.1AreaofPropellant Burning Surface(Ab).3.2 Flow Area at Nozzle Exit Plane(Ae).3.3Flow Area at Grain Port(Ap).3.4 Flow Area at Nozzle Throat(At).3.5Web ThicknessofPropellant(w).3.6Nozzle Divergence Half-Angle(a).3.7Nozzle Convergence Half-Angle(fJ).4.Impulse(I)-Impulseshall be expressed as pounds-force-seconds Obfs).A numeral inthesubscript toIindicatesthetime elapsed from zero time.Thenumeralmaybechanged to suittheapplication.4.1Action Time Impulse(Ia)-Thearea underthethrustaction time portionofthethrust-time record.4.2 Burning Time Impulse(IbJ-Thearea underthethrustburning time portionofthethrust-time record.4.3 Propellant Specific Impulse(lsp)-This symbolis usedonly in general referencetopropellant specific impulseorinreporting nonstandard corrected valuesofIspd(Notes1andIThesedefinitionsareunder the jurisdiction ofASTMCommitteeF-7onAerospaceIndustryMethodsandarethe directresponsibilityofSubcommitteeF07.02on PropellantTechnology.Current edition approvedOct.31,1980.PublishedMarch1981.OriginallypublishedasD2506-66T.Lastpreviousedition D2506-70(1980).2).All numerical values mustbeaccompanied by specifica-tionofthefollowing assumptions:4.3.1 Chamber pressure(Pc),4.3.2 Ambient pressure(Pamb),4.3.3 Nozzle area expansion ratio(E)andwhetherornotthis is optimum,and4.3.4 Nozzle divergence haIf-angle(a).NOTEI-Usethe same time interval and propellant mass assump-tions as forlopd;therefore,do not report a numerical valueoflopwithoutalso reportingthecorresponding valueoflopdNOTE2-Withthe only exceptionofSpSallreported valuesofpropellant specific impulse mustbeaccompanied by a statementoftheassumptions made in calculating a theoretical value,orastatementofthe existing motor conditions and assumptions in obtaining a measuredorcorrected value.Adegree sign()indicates a theoretical value,not avalue that has been obtained from olderived from the resultsofa motorfiring.In.stating the assumptions or motor conditions,or both,ashQrthand notation maybe usedifno confusion will result.Forexample,a measured propellant specificimpulse of241.6 Ibfs/lbm overthe25psia action time from a motor operating at 1230 psia,exhaustingto 11.6 psia withanexpansion ratio of9.8,a nozzle divergence angleof17.5deg,andanexpended massof3563 Ibm maybeabbreviated asfollows:IOpd(l230/11.6,9.8,17s,aO.2Sp.mm-mba=3563)=241.6Ibfs/lbm4.4 Theoretical Propellant Specific Impulse(rsp),calcu-lated from propellant thermodynamic properties.All numer-ical valuesmustbe accompaniedbyspecificationofthefollowing assumptions:4.4.1 Chamber pressure(Pc)4.4.2 Ambient pressure(Pamb),4.4.3 Nozzle areaexpansonratio(E)andwhetherornotthis is optimum,4.4.4 Nozzle divergence half-angle(a),4.4.5 Assumptionoffrozenorequilibrium exit composi-tion,and4.4.6 Physical stateofexhaust condensables.4.5 Measured(Delivered)Propellant Specific Impulse(ls,calculated from data fromanactualmotorfiring.Allnumerical values mustbeaccompanied by specificationofthefollowingmotorconditions:4.5.1 Chamber pressure(Pc),4.5.2 Ambient pressure(Pamb),4.5.3 Nozzle area expansion ratio(E),4.5.4 Nozzle divergence half-angle(a),4.5.5 Time interval used for impulse determination,and4.5.6 Propellant mass assumption.4.6 Theoretical Delivered Propel/(mt Specific Impulse(rspd),calculated from propellant thermodynamic propertiesassuming the samemotorconditions reported for Ispdwiththeadded specificationsofeither frozenorequilibrium exitcompositionandphysical stateofexhaust conde