室內(nèi)聲場(chǎng)的數(shù)值模擬與特征分析.pdf

1、南京理工大學(xué)碩士學(xué)位論文室內(nèi)聲場(chǎng)的數(shù)值模擬與特征分析姓名：張趙榮申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：計(jì)算數(shù)學(xué)指導(dǎo)教師：李建良20100623Abstract碩士論文AbstractTheboundaryElementMethod(BEM)iswidelyappliedtoengineeringproblemsduetoitssimplecomputationstrongadaptabilityandhighaccuracyInthispaperth

2、eindoorsoundfieldissimulatednumericallybyBEM，andtheeffectsofacousticstructuresontheacousticdiffusionofaclassroomandavocalpracticeroomarediscussedFirstBEMmodelsoftwoandthreedimensionregardingtheinterioracousticproblemsare

3、builtQuadraticdiscontinuouselementsareemployedtodealwiththecornersandimprovetheaccuracyADelaunayrefinementalgorithmisimprovedtotriangulateasimplepolygonboundaryeffectivelyanduniformlyThesingularpartofthesingularintegrali

4、sseparatedoutandiscalculatedanalyticallybytheintegrallimitorthepolartransformationThecomplexsystemequationissolvedbyacombinatorialalgorithmSecondBEMprogramsaredevelopedinC群language，andthenvalidatedbyMorse’StheoryThequadr

5、aticresiduediffuser(QRD)isapproximatedbyatransferformulaoftheacousticspecificimpedance，anditisvalidatedbythewholesurfacemodelingThird，theacousticfieldinaclassroomissimulatednumericallyusingthetwodimensionalBEMprogramThed

6、ifferencesoftheacousticdiffusionwhenterraces，QRDandabsorptivematerialofdistinctparametersareemployedontheground，theceilingandtherearwallrespectivelyarediscussedThenumericalresultsindicatethatsignificantimpmvementoftheaco

7、usticdiffusionisobtainedwhenthethreestructuresarecombinedFinally，theacousticfieldinavocalpracticeroomissimulatednumericallyutilizingthethreedimensionalBEMprogramTheeffectsoftheceilingshapeandtheabsorptivematerialposition

8、ontheacousticdiffusionareanalyzedThenumericalresultsshowthatthehighestaverageacousticdiffusionisachievedwhentheabsorptivematerialisfixedonthesidewallagainstthelowestsideoftheobliqueceilingKeywords：BoundaryElementMethodNu