1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN ISO/TR 11688-2:2001
2、 The European Standard EN ISO 11688-2:2000 has the status of a British Standard ICS 17.140.20; 21.020 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Acoustics Recommended practice for the design of low-noise machinery and equipment Part 2: Introduction to the physics of low-n
3、oise designThis British Standard, having been prepared under the direction of the Health and Environment Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 2001 BSI 03-2001 ISBN 0 580 35695 7 BS EN ISO/TR 11688-2:2001 Amendments issued si
4、nce publication Amd. No. Date Comments National foreword This British Standard is the English language version of EN ISO/TR 11688-2:2000. It is identical with ISO/TR 11688-2:1998. The UK participation in its preparation was entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/4, Ma
5、chinery noise, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments
6、and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications
7、 with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standa
8、rds Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of page
9、s This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO/TR title page, pages ii to iv, pages 1 to 46, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issue
10、d.EUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO116882 December2000 ICS17.140.20;21.020 Englishversion AcousticsRecommendedpracticeforthedesignoflownoise machineryandequipmentPart2:Introductiontothephysicsof lownoisedesign(ISO/TR116882:1998) AcoustiquePratiquerecommandepourlaconceptionde machi
11、nesetquipementsbruitrduitPartie2: Introductionlaphysiquedelaconceptionbruitrduit (ISO/TR116882:1998) AkustikRichtlinienfrdieGestaltunglrmarmer MaschinenundGerteTeil2:EinfhrungindiePhysikder LrmminderungdurchkonstruktiveManahmen(ISO/TR 116882:1998) ThisEuropeanStandardwasapprovedbyCENon17September199
12、9. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoan
13、yCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAust
14、ria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Br
15、ussels 2000CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO116882:2000EForeword ThetextoftheInternationalStandardfromTechnicalCommitteeISO/TC43“Acoustics“oftheInternational OrganizationforStandardization(ISO)hasbeentakenoverasanEuropeanStandardby
16、Technical CommitteeCEN/TC211“Akustik“,thesecretariatofwhichisheldbyDS. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidentical textorbyendorsement,atthelatestby2001,andconflictingnationalstandardsshallbewithdrawnatthe latestbyJune2001. ThisEuropeanStandardhasbee
17、npreparedunderamandategiventoCENbytheEuropeanCommission andtheEuropeanFreeTradeAssociation,andsupportsessentialrequirementsofEUDirective(s). AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,C
18、zechRepublic,Denmark, Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal, Spain,Sweden,SwitzerlandandtheUnitedKingdom. Endorsementnotice ThetextoftheInternationalStandardISO/TR116882:1998hasbeenapprovedbyCENasaEuropean Standardwithoutanymodification. ENISO1168
19、82:2000A Referencenumbe r ISO/TR116882:1998(E) TECHNICAL REPORT ISO/TR 116882 Firstedition 19980901 AcousticsRecommendedpracticefor thedesignoflownoisemachineryand equipment Part2: Introductiontothephysicsoflownoisedesign AcoustiquePratiquerecommandepourlaconceptiondemachineset quipementsbruitrduit
20、Partie2:Introductionlaphysiquedelaconceptionbruitrduit ENISO116882:2000)E(8991:288611RT/OSI ii Contents 1Scope . 1 2References . 1 3Definitions . 1 4Acousticalmodelling 1 5Controlofairborneandliquidbornenoise 2 5.1Generationoffluiddynamicnoise . 2 5.2Noisecontrolmeasures 8 6Controlofstructureborneso
21、und . 10 6.1Modelofsoundgeneration . 10 6.2Internalsources . 15 6.3Transmissionofstructurebornesound . 18 6.4Controlofstructurebornesoundtransmission bydamping . 28 6.5Radiation . 30 7Analysisbymeasurementmethods . 35 7.1Purposeoftheanalysis . 35 7.2Internalsources . 36 7.3Transmissionpaths . 36 7.4
22、Radiation . 36 7.5Summaryofproceduresfortheanalysisofexisting machinerybymeasurementmethods . 37 8Analysisbycomputationalmethods 39 8.1Purposeoftheanalysis. 39 8.2Deterministicmethods 39 8.3Statisticalmethods 39 8.4Applicabilityofcomputationalmethods . 39 AnnexAExampleoftheestimationofairbornesounde
23、mission ofamachinecausedbystructureborneandairbornesound emissionfromacomponent 41 AnnexBGlossary 44 Bibliography 46 ENISO116882:2000)E(8991:288611RT/OSI iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwide federationofnationalstandardsbodies(ISOmemberbodies).Theworkof prepar
24、ingInternationalStandardsisnormallycarriedoutthroughISO technicalcommittees.Eachmemberbodyinterestedinasubjectforwhich atechnicalcommitteehasbeenestablishedhastherighttoberepresented onthatcommittee.Internationalorganisations,governmentalandnon governmental,inliaisonwithISO,alsotakepartinthework.ISO
25、 collaboratescloselywiththeInternationalElectrotechnicalCommission (IEC)onallmattersofelectrotechnicalstandardization. ThemaintaskoftechnicalcommitteesistoprepareInternational Standards,butinexceptionalcircumstancesatechnicalcommitteemay proposethepublicationofaTechnicalReportofoneofthefollowingtype
26、s: type1,whentherequiredsupportcannotbeobtainedforthe publicationofanInternationalStandard,despiterepeatedefforts; type2,whenthesubjectisstillundertechnicaldevelopmentorwhere foranyotherreasonthereisthefuturebutnotimmediatepossibility ofanagreementonanInternationalStandard; type3,whenatechnicalcommi
27、tteehascollecteddataofadifferent kindfromthatwhichisnormallypublishedasanInternational Standard(“stateoftheart“,forexample) TechnicalReportsoftypes1and2aresubjecttoreviewwithinthreeyears ofpublication,todecidewhethertheycanbetransformedintoInternational Standards.TechnicalReportsoftype3donotnecessar
28、ilyhavetobe revieweduntilthedatatheyprovideareconsideredtobenolongervalidor useful. ISO/TR116882,whichisaTechnicalReportoftype3,waspreparedby TechnicalCommitteeISO/TC43, Acoustics,SubcommitteeSC1, Noise. ISO11688consistsofthefollowingparts,underthegeneraltitle Acoustics Recommendedpracticeforthedesi
29、gnoflownoisemachineryand equipment: Part1:Planning Part2:Introductiontothephysicsoflownoisedesign ENISO116882:2000E(8991:288611RT/OSI) iv Introduction TheobjectiveofthispartofISO/TR11688isnoisereductioninexisting machineryandnoisecontrolatthedesignstageofnewmachinery. Itisimportantthatnonacousticeng
30、ineersareengagedinnoisecontrol practice.Itisofgreatimportancefortheseengineerstohaveabasic knowledgeofnoisegenerationandpropagationcharacteristicsandto understandtheprinciplesofnoisecontrolmeasures. ENISO116882:2000LACINHCET TROPER O)E(8991:288611RT/OSI 1 AcousticsRecommendedpracticeforthedesignoflo
31、wnoise machineryandequipment Part2: Introductiontothephysicsoflownoisedesign 1Scope ThispartofISO/TR11688providesthephysicalbackgroundforthelownoisedesignrulesandexamplesgivenin ISO/TR116881 1) andsupportstheuseofextensivespecialliterature. Itisintendedforusebydesignersofmachineryandequipmentaswella
32、susersand/orbuyersofmachinesand authoritiesinthefieldoflegislation,supervisionorinspection. EquationsgiveninthisTechnicalReportwillimprovethegeneralunderstandingofnoisecontrol.Inmanycases theyallowacomparisonofdifferentversionsofdesign,buttheyarenotusefulforthepredictionofabsolutenoise emissionvalue
33、s. Informationoninternalsoundsources,transmissionpathsandsoundradiatingpartsofamachineisthebasisfor noisecontrolinmachines.Thereforemeasurementmethodsandcomputationalmethodssuitabletoobtainthis informationaredescribedinclauses7and8andannexA. 2References SeeISO/TR116881andthebibliography. 3Definition
34、s SeeISO/TR116881andannexA. 4Acoustical modelling Inordertofacilitatetheunderstandingofcomplexsoundgenerationandpropagationmechanismsinmachineryand equipmentorvehicles(thelatterarealsocalled“machines“inthispartofISO/TR11688),itisnecessarytocreate simpleacousticalmodels.Themodelsprovideabasisfornoise
35、controlmeasuresatthedesignstage. 1) ISO/TR116881:1995, AcousticsR ecommendedpracticeforthedesignoflow noisem achineryandequipm entPart1: Planning. ENISO116882:2000E(8991:288611RT/OSI) 2 Auniversalapproachistodistinguishbetween internalsources; transmissionpathsinsidethemachine; radiationfromitsbound
36、aries. Theinternalsourcesandthetransmissionpathscaneachbeassignedtothreecategoriesaccordingtothemedia used: airborne; liquidborne; structureborne. Radiationisconsideredforaironly. Figures1and2servetoillustratetheprincipleofacousticalmodelling.Figure1showsasimplifiedmachine consistingofanelectricmoto
37、randahousingwithanopeninginit. Themotoristheonlyinternalsource.Itgeneratesairborneandstructurebornesound. Therearethreeinternaltransmissionpaths: throughtheairinsidethehousingtotheopening; throughtheairinsidethehousingtothewallsofthehousing; throughthefasteningstothewallsofthehousing. Radiationoccur
38、sfromtheopeningandfromthewallsofthehousing. Figure2illustratesthisinablockdiagram. Thetotalsoundpoweremittedfromthemachineisthesumofthethreecontributions. Asystematicapproachstartswithanassessmentoftherelativeimportanceofthesecontributions.Thenextstepis examiningtheblocksinFigure2lookingforpossib il
39、itiestoreducesourcestrength,transmissionand/orradiation (seealsofollowingclauses).Thisshouldbedoneinrelationtothevariousaspectsofthedesignprocess(see ISO/TR116881:1995,Figure1). 5 Controlofairborneandliquidbornenoise Thebasicprinciplesofgeneration,transmissionandradiationofsoundinair(orothergases)an
40、dliquidsare basicallyidenticalandarethereforeconsideredtogetherinthisclause.Thereisonlyoneimportantexception: cavitation.Occurringinliquidsonly,thisphenomenonisconsideredseparatelyin5.1.3. 5.1 Generationoffluiddynamicnoise Importantnoisegeneratingphenomenaingasesandliquidsareturbulence,pulsationands
41、hock.Fluiddynamic processesgeneratenoiseifflowrateandpressurevaryovertimeinalimitedvolumeofaliquidoragas,for exampleinaturbulentflow.Thisleadstothetransmissionofsoundfromthedisturbedvolumeofthefluidtothe surroundingmedium.Aclassicexampleofthisistheescapeofcompressedairfromanozzle. ENISO116882:2000)E
42、(8991:288611RT/OSI 3 Figure1Simplifiedmachinefortheillustrationofacousticalmodelling Figure2Blockdiagramfortheillustrationofgeneration,transmissionandradiationofsoundinthe “machine“ofFigure1 Mechanismsoffluiddynamicsoundgenerationcanberelatedtopropertiesofelementarysoundsourceswith knowncharacterist
43、ics: monopoles; dipoles; quadrupoles. 5.1.1 Elementarymodelsources Amonopolesourceisaninphasevolumechange,suchasapulsatingvolumeofanyshapeorapistoninalarge rigidsurface.Inthefarfield,monopoleshaveasphericalradiationpattern.Thesoundradiatedfromamonopole sourcecanbereducedbyreducingthetemporalvariationinthevolumeflowrate. EXAMPLE 1:Outletsofinternalcombustionengines,rotarypistonfans,multicellcompressors,pistonpumps,piston compressors,flares. Adipole sourcearisesasaresultofexternaltimevariableforcesactingonafluidwithoutvolumechange,suchas inanoscill
