穿孔板吸声结构地吸声性能及其优化

《穿孔板吸声结构地吸声性能及其优化》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、江苏大学硕士学位论文微穿孔板吸声结构的吸声性能及其优化姓名：祝瑞银申请学位级别：硕士专业：环境工程指导教师：赵晓丹20070601江苏大学工程硕士学位论文摘要本文根据马大猷教授的微穿孔吸声理论，讨论了微穿孔板吸声结构的基本特性。计算研究了单层微穿孔板吸声结构的吸声系数，影响微穿孔板吸声结构吸声性能的参数主要有穿孔孔径、板的厚度、穿孔率及空腔深度。通过理论计算和实验数据对这些参数进行分析，得到微穿孔板的吸声特性：穿孔率小对获得高的穿孔吸声系数有利，穿孔率不宜超过4％；在条件容许的情况下，背腔深度宜尽可能大，对提高低频的吸声系数有利；孔径则是以尽可能小为好；选用较厚的板也可以提高吸声系数

2、。进一步对双层微穿孔板结构进行了研究．在单层微穿孔板计算方法的基础上，进行了双层微穿孔板吸声系数的计算，与单层微穿孔板进行了比较，说明了双层结构研究的重要性。应用遗传算法对其结构参数进行了优化，结果表明，双层微穿孔板在经过遗传算法优化之后，在所选频率范围内能够获得饱满的吸声系数曲线，与未优化的双层结构相比，吸声性能有了显著的提高，不仅得到了高的吸声系数，而且吸声频带也相应加宽，通过实验也验证了理论计算的正确性。为实际工程应用提供了理论基础。关键词：噪声控制；微穿孔板；吸声系数；遗传算法；优化设计。江苏大学工程硕士学位论文ABSTRACTBasedonMaDayou'smicro-pe

3、rforatedpanelabsorbingtheory,thisthesisdiscussedthefundamentalpropertyofmicro—perforatedpanelabsorber．Theparametersthataffecttheabsorptioncharacteristicsofmicro-perforatedpanelaletheperforation-aperture，thethicknessofperforatedpanel，theperforationarearatioandthedepthofthecavity．Theseparametersh

4、avebeenanalyzedbytheoreticalcalculationandtheresultofexperiment．Thefollowingabsorptivecharacteristicsofmicro-perforatedpanelabsorberhavebeenfound．Itisbenefittoselectanduselessperforationrateandtheperforationrateusuallyshouldbenotmorethan4％．Underthepossibleconditionitisbettertoselectthelongdepth

5、ofthecaVitywhichishelpfultoimproveabsorptioncoefficientinlowfrequency．Inusualtheperforation-apertureshouldbeassmallaswhichitcanbemachined．Usingthickermicro—perforatedpanelisalsobenefitforgettinghigheracousticsabsorptioncoefficient．Further,doublelayermicro—perforatedpanelstructureisresearched．Ma

6、kingUSeofthesinglelayermicro—perforationpanelreckoning，theacousticsabsorptioncoefficientofdoublelayermicro-perforatedpanelstructureiscalculated．Comparingwithsinglelayermicro-perforationpanel，doubMlayermicro-perforatedpanelstructurehashigheracousticabsorptionability．Doublelayermicro-perforatedpa

7、nelstructureisresearchedtobeopthnizedbytheGeneticalgorithmmethod．Itisnotedthatafteroptimizationdoublelayermicro-perforatedpanelstructurec孤getmoresatisfactoryabsorptioncurve．ItsacousticscharacteristicshavebeimprovedaloLbothinitsaco