汽车车内噪声预测与控制研究

重庆大学硕士学位论文汽车车内噪声预测与控制研究姓名：赵金斗申请学位级别：硕士专业：车辆工程指导教师：邓兆祥20050501I--2dBAIIIABSTRACTApplyingFEM,BEMandothermoderndesignandanalysismethodtoanalyze,forecastandcontrolcarinteriornoiseisaresearchhotpoint.Domesticresearchinthisfieldisimmatureandtherearefewsuccessfulinstances.Combiningthedevelopmentofanewcar,theanalysisandforecastofcarinteriornoiseanditsinfluencefactorandcontrolmeasuresisattemptedinthedissertation,whichcanprovidetheoreticalsupportforcarinteriornoiseandimprovethecarinteriornoisequalityontheonehandandtrytofindoutacompleteforecast,analysisandcontrolmethodsoastoenrichtheresearchoflowcarinteriornoiseontheotherhand.First,thefiniteelementmodelofcarbody,acousticfiniteelementmodelofcompartmentcavitysoundfieldandthestructure-acousticcouplingfiniteelementmodelofcarbodystructure-compartmentsoundfieldareestablished.Then,afurtherresearchonthedynamiccharacteristicsofthecarbodystructure,acousticcharacteristicsofcompartmentcavitysoundfieldandthedynamiccharacteristicsofcarbodystructure-compartmentcavitysoundfieldstructure-acousticcouplingsystemiscarriedoutbymeansofdynamicanalyticaltechnologyforstructureandsoundfield.Onthisbasis,thedissertationanalyzescarcompartmentacousticresponseofcouplingsystembythestimulationofthemotorandroadsurface.Theresultshowsthatthesoundpressurelevelincreasewiththeincreaseofmotorspeedandnoapparentformantappearsintherangeoftheengineoperatingspeed.Theresultalsoshowsthatthesoundpressurelevelofthemeasuringpointinthebackseatishigherthanthatinthefrontseatandthepressurelevelofthemeasuringpointinrightpassengerpositionishigherthanthatinthedriverposition.Furtherpanelacousticcontributionanalysisshowsthatfrontfloorboard,rearfloorboard,firewallandroofpanelhavemuchcorrelationwiththenoisecausedbythefrontandbackseatsandismainlycontributedtocarinteriornoise.Atlast,thepaperstudiedthefactors,whichinfluencethespreadofthenoiseinthecar.Onthisbasisandcombiningcharacteristicsofthecar,correspondingimprovingandcontrolmeasuresareputforward.Theanalyticalresultshowsthatthesoundpressureleveldecrease2dbAaveragely,thusthequalityofcarinteriornoiseisimproved.Keywords:Carinteriornoise,Forecastandcontrol,Dynamiccharacteristics,Acousticcharacteristics,Acousticresponse,Acousticcontribution1111.1[1][2][3][4][1]1.1()()1.1Fig1.1theMainSourcesandPropagationPathoftheInteriorNoise2800Hz500Hz1.2()ACraggsTShuku[9][10][11][12][13][14][15]()13()20200Hz20Hz200HzNASTRANNASTRAN[7]NASTRAN,ANSYSANSYS()LMSSYSNOISE(FEA)(BEA)(SEA)4[8][43][7]1.3--1.-()2.SYSNOISE153.4.2722.1[31]2.1.12.1[21]15mm30mm45mm45mm2.2Shell63113649988599282.3Shell6314743129728778322.1Fig2.1Themodelofcarbody292.1.2Subspace[24]102.12.1Table2.1TheresultofthemodalanalysisofbodyinwhiteHz29.91638.62553.24367.93673.648Hz74.23576.8284.6490.25799.43229.916Hz38.652Hz2.4Fig2.4Thefirstandsecondmodalofbodyinwhite2.2Fig2.2Thefinitemodelofbodyinwhite2.3Fig2.3Thefinitemodeofwholecarbody1053.243Hz67.936Hz73.648Hz74.235Hz2.5Fig2.5Thethirdandfourthmodalofbodyinwhite2.6Fig2.6Thefifthandsixthmodalofbodyinwhite21176.82Hz84.64Hz90.257Hz99.432Hz100Hz29.916Hz38.652Hz53.243Hz2.7Fig2.7Theseventhandeighthmodalofbodyinwhite2.8Fig2.8theninthandtenthmodalofbodyinwhite120-60Hz20-60Hz,9Hz2.1.3a58.602Hzb67.932Hzc130.629Hzd153.927Hz2.9Fig2.9Thestructuremodalofcarbody213Subspace200Hz2.22.92.2HzTable2.2Theresultofthemodalanalysisofcarbody717.5213692.172817.5423798.633919.42138105.3451021.43839114.6361128.91940115.4481231.16941118.5381335.69742120.9331438.29543125.0741541.31244130.6291643.51245132.3681744.20546137.311853.37447145.0471955.23948149.6542058.60249151.882161.6250153.9272262.71651157.0222364.3152160.12466.37653167.7772566.873541702667.32655176.8082767.93656179.0392871.27557188.5312974.27758191.243143077.40959193.743178.39560194.0833283.27761195.0633385.73962198.2133487.84363200.7573590.24664203.8182.2()2.2.1[7][8][22](2.1)222201ppct∂∇=∂(2.1)215P()(),,,PxyztT(2.2)jtPpeω=(2.2)ppj1−ωfπω2=f0=Φ(2.1)Helmholtz(2.3)2220ppcω∇+⋅=(2.3)(2.1)(2.4)22210ppct∂⋅−∇⋅∇=∂(2.4){}∂∂∂∂∂∂==⋅∇zy()xLT{}L=∇()(2.4){}{}()22210TpLLpct∂⋅−=∂(2.5)GalerkinPδ{}{}(){}{}()2()()()221TTvolvolsvolvolsppdLpLpdnpLpdctδδδ∂⋅+=∂∫∫∫(2.6)16volpδ()(),,,pxyztδ=S{}nS{}{}{}{}202unpntρ∂⋅∇=−⋅∂(2.7){}u{}{}(){}{}202TTnLpnutρ∂⋅=−⋅∂(2.8)(2.8)(2.6){}{}(){}{}22()()0()2221TTvolvolsvolvolsppdLpLpdpnudcttδδρδ∂∂⋅+=−⋅∂∂∫∫∫(2.9)(2.9)Puvw(2.10)(2.11){}{}TepNp=(2.10){}{}'TeuNU=(2.11){}N{}'N{}ep{}{}eeuU={}ev{}ew{}{}[]{}{}00TppeeeeeeMPKPRUρ++=&&&&(2.12)217[]{}{})(21volvolTpedNNcM∫=[][][])(volvolTpedBBK∫=[]{}{}{})(00sTTsedNnNR′=∫ρρ2.2.2[7][8][22]PPnctβ∂∂=−∂∂(2.13)rc0ρβ=rD(2.14)()01scPDPdSrctρδ∂=⋅∂∫(2.14)(2.9)(2.15){}{}()(){}{}20()()2220()211TvolvolvolvolsTsscpPLpLpdpdPdSctrctpnudtρδδδρδ∂∂+⋅+⋅∂∂∂=−⋅∂∫∫∫∫(2.15)(2.10)PD(2.16){}{}{}()01TTeescPDPNNdSrctρδ∂=∂∫(2.16){}∂∂=tPPee&(2.17){}{}{}[]{}00TpppeeeeeeeeMPCPKPRUρ+++=&&&&&(2.17)18[]{}{}()SdNNcCsTpe∫=β2.2.3[8]eU&&=eU&=eU=0eU&&=eU&=eU=0(2.12){}{}{}0ppeeeeMPKP+=&&(2.18)2{[][]}{}0PPeeeKMPω−=(2.19)eU&&=eU&=eU=0(2.17){}{}{}0pppeeeeeeMPCPKP++=