Rigidly-backed micro-perforated panels (MPPs) are Helmholtz-type absorbers whose performance is usually limited to narrow frequency ranges. Multi-layer or multi-array partitions enable to extend their absorption properties over a broader bandwidth. Optimal selection of their parameters often leads to a distribution of macro and micro-perforated panels constitutive of the overall partition. However, there is not yet a full consensus on a unified impedance model whose end-correction terms may contribute to the dissipation of both macro- and micro-perforated panels. In this study, an enhanced multi-modal approach is formulated that is able to describe the dissipative and reactive properties of multi-layer backed or unbacked macro-or micro-perforated partitions. It provides a unit cell transfer impedance that accounts for visco-thermal boundary layers (VTBLs) and high-order evanescent modes within the perforation and at the panel walls. It is validated against Finite Element Visco-Thermal Acoustics models, but at a much lower computational cost. It is shown that the presence of VTBLs over the solid surfaces cannot be neglected for perforates with a thickness-to-hole diameter ratio lower than 0.5 or for multi-layer acoustic fishnets with thin air gaps lower than six times the VTBLs thickness.
{"title":"Enhanced modal matching approach to efficiently predict the acoustical performance of macro- and micro-perforated partitions","authors":"C. Maury, T. Bravo","doi":"10.1121/2.0001429","DOIUrl":"https://doi.org/10.1121/2.0001429","url":null,"abstract":"Rigidly-backed micro-perforated panels (MPPs) are Helmholtz-type absorbers whose performance is usually limited to narrow frequency ranges. Multi-layer or multi-array partitions enable to extend their absorption properties over a broader bandwidth. Optimal selection of their parameters often leads to a distribution of macro and micro-perforated panels constitutive of the overall partition. However, there is not yet a full consensus on a unified impedance model whose end-correction terms may contribute to the dissipation of both macro- and micro-perforated panels. In this study, an enhanced multi-modal approach is formulated that is able to describe the dissipative and reactive properties of multi-layer backed or unbacked macro-or micro-perforated partitions. It provides a unit cell transfer impedance that accounts for visco-thermal boundary layers (VTBLs) and high-order evanescent modes within the perforation and at the panel walls. It is validated against Finite Element Visco-Thermal Acoustics models, but at a much lower computational cost. It is shown that the presence of VTBLs over the solid surfaces cannot be neglected for perforates with a thickness-to-hole diameter ratio lower than 0.5 or for multi-layer acoustic fishnets with thin air gaps lower than six times the VTBLs thickness.","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125599982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Panfilova, Xufei Chen, R. J. Sloun, H. Wijkstra, M. Mischi, O. Sapozhnikov
B/A holds promise as a biomarker for tissue characterization. Moreover, measuring B/A enables identifying isomer types in biological liquids, potentially aiding diagnosis of some diseases. The standard finite amplitude insert-substitution method of measuring B/A has several limitations. It assumes a linear dependency of the attenuation coefficient on frequency, limiting it to tissue applications, and necessitates sample positioning close to the receiver. Here we propose the generalized finite amplitude insert-substitution method, which allows for B/A measurement of tissues and liquids, and gives freedom in sample positioning. In this work, we present the derived formula and validate the experimental procedure. For this purpose, B/A measurements of corn oil, porcine fat and porcine liver were conducted. For each substance, several conditions were tested, including various distances between the source and the receiver, various sample positions and amplitudes of the transmitted pulses. A better agreement with literature data was found for lower source pressure amplitudes and distances within the near field of the source transducer. In these conditions, the measurement error was confined to 8% and 25% of the literature values of corn oil and the considered tissues, respectively. No clear indication of the influence of sample position on the measurement accuracy was found.
{"title":"The generalized finite amplitude insert-substitution method for B/A measurement of tissues and liquids","authors":"A. Panfilova, Xufei Chen, R. J. Sloun, H. Wijkstra, M. Mischi, O. Sapozhnikov","doi":"10.1121/2.0001439","DOIUrl":"https://doi.org/10.1121/2.0001439","url":null,"abstract":"B/A holds promise as a biomarker for tissue characterization. Moreover, measuring B/A enables identifying isomer types in biological liquids, potentially aiding diagnosis of some diseases. The standard finite amplitude insert-substitution method of measuring B/A has several limitations. It assumes a linear dependency of the attenuation coefficient on frequency, limiting it to tissue applications, and necessitates sample positioning close to the receiver. Here we propose the generalized finite amplitude insert-substitution method, which allows for B/A measurement of tissues and liquids, and gives freedom in sample positioning. In this work, we present the derived formula and validate the experimental procedure. For this purpose, B/A measurements of corn oil, porcine fat and porcine liver were conducted. For each substance, several conditions were tested, including various distances between the source and the receiver, various sample positions and amplitudes of the transmitted pulses. A better agreement with literature data was found for lower source pressure amplitudes and distances within the near field of the source transducer. In these conditions, the measurement error was confined to 8% and 25% of the literature values of corn oil and the considered tissues, respectively. No clear indication of the influence of sample position on the measurement accuracy was found.","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128713738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of the supporting table on initial transients of the fretted zither: An impulse pattern formulation model","authors":"Simon Linke, R. Bader, R. Mores","doi":"10.1121/2.0001494","DOIUrl":"https://doi.org/10.1121/2.0001494","url":null,"abstract":"","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127929960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Summary of Acoustics-in-Focus Panel Discussion Special Session\u0000 “Underwater Sound Modeling: Comprehensive Environmental\u0000 Descriptions”","authors":"T. Duda, B. Cornuelle","doi":"10.1121/2.0001469","DOIUrl":"https://doi.org/10.1121/2.0001469","url":null,"abstract":"","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114812328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miwako Hisagi, Eve Higby, Mike Zandona, Justin Kent, Daniela Castillo, Ingrid Davidovich, V. Shafer
{"title":"Perceptual discrimination measure of non-native phoneme perception in early and late Spanish-English & Japanese-English bilinguals","authors":"Miwako Hisagi, Eve Higby, Mike Zandona, Justin Kent, Daniela Castillo, Ingrid Davidovich, V. Shafer","doi":"10.1121/2.0001424","DOIUrl":"https://doi.org/10.1121/2.0001424","url":null,"abstract":"","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129652049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aaron B. Vaughn, K. Gee, Kevin M. Leete, J. Downing
{"title":"Near to far field correlation of crackle-related events in military aircraft jet noise","authors":"Aaron B. Vaughn, K. Gee, Kevin M. Leete, J. Downing","doi":"10.1121/2.0001442","DOIUrl":"https://doi.org/10.1121/2.0001442","url":null,"abstract":"","PeriodicalId":300779,"journal":{"name":"180th Meeting of the Acoustical Society of America","volume":"26 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121763707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：