Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet
This study was conducted to improve the sound absorption dips in nonwoven fabric sheets with a back air space. Considering the particle velocity distribution in the back air space, another nonwoven sheet was added to divide the air space into layers. The sound absorption coefficient of the sound-abs...
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| Format: | Article |
| Language: | English |
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MDPI AG
2025-04-01
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| Series: | Acoustics |
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| Online Access: | https://www.mdpi.com/2624-599X/7/2/25 |
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| author | Shuichi Sakamoto Kodai Sato Gaku Muroi Yusuke Nakao Kaito Kuboki Nobuhito Taguchi |
| author_facet | Shuichi Sakamoto Kodai Sato Gaku Muroi Yusuke Nakao Kaito Kuboki Nobuhito Taguchi |
| author_sort | Shuichi Sakamoto |
| collection | DOAJ |
| description | This study was conducted to improve the sound absorption dips in nonwoven fabric sheets with a back air space. Considering the particle velocity distribution in the back air space, another nonwoven sheet was added to divide the air space into layers. The sound absorption coefficient of the sound-absorbing structure was theoretically derived using the transfer matrix method. The nonwoven sheet model with the Rayleigh model and the air space behind the nonwoven sheet were mathematically represented using the transfer matrix. The transfer function method was employed to combine the transfer matrices to obtain the sound absorption coefficient. A two-microphone acoustic impedance tube was used to measure the sound absorption coefficient, and the theoretical and experimental values were compared. The sound absorption dip of the first order was improved by placing a nonwoven sheet at a position half the thickness of the back air space. It was theoretically predicted that placing the nonwoven sheet at 1/4 of the back air space thickness from the rigid wall would improve the first- and second-order sound absorption dips. By selecting the conditions, a similar trend was observed during the experiments. The study shows that the higher the ventilation resistance of the added nonwoven fabric sheet, the more improved the sound absorption dip. |
| format | Article |
| id | doaj-art-1c5b4aa8ec1b4841b51661bb599e58b3 |
| institution | Kabale University |
| issn | 2624-599X |
| language | English |
| publishDate | 2025-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Acoustics |
| spelling | doaj-art-1c5b4aa8ec1b4841b51661bb599e58b32025-08-20T03:24:26ZengMDPI AGAcoustics2624-599X2025-04-01722510.3390/acoustics7020025Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric SheetShuichi Sakamoto0Kodai Sato1Gaku Muroi2Yusuke Nakao3Kaito Kuboki4Nobuhito Taguchi5Department of Engineering, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanGraduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanGraduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanGraduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanGraduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanGraduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata 950-2181, JapanThis study was conducted to improve the sound absorption dips in nonwoven fabric sheets with a back air space. Considering the particle velocity distribution in the back air space, another nonwoven sheet was added to divide the air space into layers. The sound absorption coefficient of the sound-absorbing structure was theoretically derived using the transfer matrix method. The nonwoven sheet model with the Rayleigh model and the air space behind the nonwoven sheet were mathematically represented using the transfer matrix. The transfer function method was employed to combine the transfer matrices to obtain the sound absorption coefficient. A two-microphone acoustic impedance tube was used to measure the sound absorption coefficient, and the theoretical and experimental values were compared. The sound absorption dip of the first order was improved by placing a nonwoven sheet at a position half the thickness of the back air space. It was theoretically predicted that placing the nonwoven sheet at 1/4 of the back air space thickness from the rigid wall would improve the first- and second-order sound absorption dips. By selecting the conditions, a similar trend was observed during the experiments. The study shows that the higher the ventilation resistance of the added nonwoven fabric sheet, the more improved the sound absorption dip.https://www.mdpi.com/2624-599X/7/2/25sound absorption dipnonwoven fabric sheettransfer matrixback airspace |
| spellingShingle | Shuichi Sakamoto Kodai Sato Gaku Muroi Yusuke Nakao Kaito Kuboki Nobuhito Taguchi Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet Acoustics sound absorption dip nonwoven fabric sheet transfer matrix back airspace |
| title | Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet |
| title_full | Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet |
| title_fullStr | Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet |
| title_full_unstemmed | Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet |
| title_short | Improvement of Sound-Absorbing Dips in Nonwoven Fabric Sheet with Back Air Space: Division of Back Air Space by Additional Nonwoven Fabric Sheet |
| title_sort | improvement of sound absorbing dips in nonwoven fabric sheet with back air space division of back air space by additional nonwoven fabric sheet |
| topic | sound absorption dip nonwoven fabric sheet transfer matrix back airspace |
| url | https://www.mdpi.com/2624-599X/7/2/25 |
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