资源描述：
《Improvement of the Delany-Bazley and Miki models for fibrous sound-absorbing materials-2007》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、Acoust.Sci.&Tech.29,2(2008)#2008TheAcousticalSocietyofJapanPAPERImprovementoftheDelany-BazleyandMikimodelsforfibroussound-absorbingmaterialsTakeshiKomatsuIndustrialResearchInstituteofShizuokaPrefecture,2078Makigaya,Aoi-ku,Shizuoka,421–1298Japan(Received15January2007,Acceptedforpubli
2、cation23July2007)Abstract:Anewmodelforpredictingtheacousticalpropertiesoffibrousmaterials,thecharacteristicimpedanceZcandthepropagationconstant,onlyfromtheirairflowresistivitywasconstructed.TheDelany-BazleyandMikimodelsarewellknownasconventionalpredictionmethods.Theirformulasaresimila
3、r,andtheirdifferenceisinthevaluesofcoefficientsanddegreesintheformulas.Inthisresearch,theacousticalpropertiesandairflowresistivityoffibrousmaterials,15typesofglasswooland9typesofrockwool,weremeasuredandcomparedwithvaluesobtainedbyconventionalmethodsofprediction.Itwasfoundthattheintroduct
4、ionofanexpressioninvolvingthecommonlogarithmimprovedtheconventionalmodels.Thisnewmodelismoreeffectivethantheconventionalmodels,particularlyforthepredictionforhigh-densityfibrousmaterialswheref=<0:01m3/kgandlow-densityoneswheref=>0:1m3/kg.Keywords:Acousticalproperties,Absorptioncoeffic
5、ients,Characteristicimpedance,Propagationconstant,FibrousmaterialsPACSnumber:43.55.Ev[doi:10.1250/ast.29.121]1.INTRODUCTION2.PREDICTIONEXPRESSIONSDelanyandBazley,andMikihavepresentedexpres-Theacousticalpropertiesofaporoussound-absorbingsionsthatpredicttheacousticalpropertiesofporous
6、sound-material,thatis,thecharacteristicimpedanceZcandtheabsorbingmaterialsonlyfromtheirairflowresistivity[1,2].propagationconstant,canbegivenasthecomplexTheseexpressionsarewidelyappliedtofibrousmaterialsatexpressionsasfollows:present[3–5].Zc¼RþjXð1ÞDelanyandBazleyproposedexpressionsba
7、sedonexperimentaldataobtainedfromglasswoolandrock¼þj ;ð2Þwool.MikiamendedthecoefficientsanddegreestowhereRistherealcomponent,Xistheimaginarysatisfythepositive-realpropertyoftherealandimagi-component,istheattenuationconstantinnepers/mnarypartsoftheseexpressions.Itwasinthe1960s(1neper¼
8、8.686dB),¼!=cisthep
