Experimental study on aerodynamic sound generated from flow around a forward facing step
Aerodynamic noise in high frequency band related in the flows around A-pillar is easily propagated to the cabin of the automobile. Understanding of the characteristics of the aerodynamic noise is needed to reduce the cabin noise. Moreover, understanding of the separated shear layer which is strongly...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2023-04-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/18/1/18_2023jfst0020/_pdf/-char/en |
| _version_ | 1797835602809323520 |
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| author | Yoshihiro SHIRASU Yasumasa SUZUKI Chisachi KATO |
| author_facet | Yoshihiro SHIRASU Yasumasa SUZUKI Chisachi KATO |
| author_sort | Yoshihiro SHIRASU |
| collection | DOAJ |
| description | Aerodynamic noise in high frequency band related in the flows around A-pillar is easily propagated to the cabin of the automobile. Understanding of the characteristics of the aerodynamic noise is needed to reduce the cabin noise. Moreover, understanding of the separated shear layer which is strongly affected by the condition of the step hight H to the boundary layer thickness δ is needed. In this study, far field sound and correlation measurement of flow velocity are measured to investigate the characteristics of aerodynamic noise and the relationship between H/δ and turbulence length scale L as eddy scale for the forward facing step. As a result, multiple gradual peaks in more than 1 kHz are observed in the aerodynamic sound spectra. Furthermore, it is found that turbulence length scale L increases for increasing of H/δ and turbulence length scale to step height for H/δ = 2.0 is almost equal to that for H/δ = 3.0. Then, it is clear that spectral peaks are strongly affected by step height. And it is confirmed that H/δ = 2.0 and 3.0 are equal in turbulence length scale to the step height. |
| first_indexed | 2024-04-09T14:56:14Z |
| format | Article |
| id | doaj.art-481d86ddb093442580609169e9a77ea0 |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-04-09T14:56:14Z |
| publishDate | 2023-04-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-481d86ddb093442580609169e9a77ea02023-05-02T04:54:02ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582023-04-01181JFST0020JFST002010.1299/jfst.2023jfst0020jfstExperimental study on aerodynamic sound generated from flow around a forward facing stepYoshihiro SHIRASU0Yasumasa SUZUKI1Chisachi KATO2Research Group, Research & Development Center, DMW CorporationDepartment of Mechanical Engineering, Nihon UniversityInstitute of Industrial Science, the University of TokyoAerodynamic noise in high frequency band related in the flows around A-pillar is easily propagated to the cabin of the automobile. Understanding of the characteristics of the aerodynamic noise is needed to reduce the cabin noise. Moreover, understanding of the separated shear layer which is strongly affected by the condition of the step hight H to the boundary layer thickness δ is needed. In this study, far field sound and correlation measurement of flow velocity are measured to investigate the characteristics of aerodynamic noise and the relationship between H/δ and turbulence length scale L as eddy scale for the forward facing step. As a result, multiple gradual peaks in more than 1 kHz are observed in the aerodynamic sound spectra. Furthermore, it is found that turbulence length scale L increases for increasing of H/δ and turbulence length scale to step height for H/δ = 2.0 is almost equal to that for H/δ = 3.0. Then, it is clear that spectral peaks are strongly affected by step height. And it is confirmed that H/δ = 2.0 and 3.0 are equal in turbulence length scale to the step height.https://www.jstage.jst.go.jp/article/jfst/18/1/18_2023jfst0020/_pdf/-char/enwind tunnel experimentforward facing stepseparated flowaerodynamic soundturbulencelength scale |
| spellingShingle | Yoshihiro SHIRASU Yasumasa SUZUKI Chisachi KATO Experimental study on aerodynamic sound generated from flow around a forward facing step Journal of Fluid Science and Technology wind tunnel experiment forward facing step separated flow aerodynamic sound turbulence length scale |
| title | Experimental study on aerodynamic sound generated from flow around a forward facing step |
| title_full | Experimental study on aerodynamic sound generated from flow around a forward facing step |
| title_fullStr | Experimental study on aerodynamic sound generated from flow around a forward facing step |
| title_full_unstemmed | Experimental study on aerodynamic sound generated from flow around a forward facing step |
| title_short | Experimental study on aerodynamic sound generated from flow around a forward facing step |
| title_sort | experimental study on aerodynamic sound generated from flow around a forward facing step |
| topic | wind tunnel experiment forward facing step separated flow aerodynamic sound turbulence length scale |
| url | https://www.jstage.jst.go.jp/article/jfst/18/1/18_2023jfst0020/_pdf/-char/en |
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