Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole
To control and reduce the rear separation region and the vortex of the free-end surface, a passive flow control method that is to use an inclined flow controlling hole (FCH) passing through the free-end surface to the side of the rear surface was proposed for a low aspect ratio (=1) circular cylinde...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2017-03-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0006/_pdf/-char/en |
| _version_ | 1819282253690175488 |
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| author | Hiroka RINOSHIKA Akira RINOSHIKA Shun FUJIMOTO |
| author_facet | Hiroka RINOSHIKA Akira RINOSHIKA Shun FUJIMOTO |
| author_sort | Hiroka RINOSHIKA |
| collection | DOAJ |
| description | To control and reduce the rear separation region and the vortex of the free-end surface, a passive flow control method that is to use an inclined flow controlling hole (FCH) passing through the free-end surface to the side of the rear surface was proposed for a low aspect ratio (=1) circular cylinder. The high-speed PIV (Particle Image Velocimetry) measurements were performed at Reynolds number of 8,570 in a circulation water tunnel in order to compare the flow characteristics between the controlling and no-controlling wakes. Furthermore, to study the position effect of the FCH, there kinds of the FCH models were tested. It was found that the fluid flows from the large rear recirculation zone upwards to the small recirculation zone on the free end surface through the FCH. The size of rear recirculation zone was reduced by the FCH cylinders with h = 50 mm, and the FCH cylinders with h = 20 and 35 mm effectively diminished the separation region of the free end surface. Meanwhile, vorticity, Reynolds shear stresses and turbulent kinetic energy were also decreased by the FCH cylinders with h = 50 mm comparing with the standard cylinder and other FCH models. Spectral analyses suggest that the dominate frequency of vortex shedding from the cylinder surface increases. |
| first_indexed | 2024-12-24T01:12:39Z |
| format | Article |
| id | doaj.art-0b37450a03c7425ea384e78ceed7392d |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-12-24T01:12:39Z |
| publishDate | 2017-03-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-0b37450a03c7425ea384e78ceed7392d2022-12-21T17:22:51ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582017-03-01121JFST0006JFST000610.1299/jfst.2017jfst0006jfstPassive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined holeHiroka RINOSHIKA0Akira RINOSHIKA1Shun FUJIMOTO2Department of Mechanical Systems Engineering, Yamagata UniversityDepartment of Mechanical Systems Engineering, Yamagata UniversityDepartment of Mechanical Systems Engineering, Yamagata UniversityTo control and reduce the rear separation region and the vortex of the free-end surface, a passive flow control method that is to use an inclined flow controlling hole (FCH) passing through the free-end surface to the side of the rear surface was proposed for a low aspect ratio (=1) circular cylinder. The high-speed PIV (Particle Image Velocimetry) measurements were performed at Reynolds number of 8,570 in a circulation water tunnel in order to compare the flow characteristics between the controlling and no-controlling wakes. Furthermore, to study the position effect of the FCH, there kinds of the FCH models were tested. It was found that the fluid flows from the large rear recirculation zone upwards to the small recirculation zone on the free end surface through the FCH. The size of rear recirculation zone was reduced by the FCH cylinders with h = 50 mm, and the FCH cylinders with h = 20 and 35 mm effectively diminished the separation region of the free end surface. Meanwhile, vorticity, Reynolds shear stresses and turbulent kinetic energy were also decreased by the FCH cylinders with h = 50 mm comparing with the standard cylinder and other FCH models. Spectral analyses suggest that the dominate frequency of vortex shedding from the cylinder surface increases.https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0006/_pdf/-char/enflow controlling holepassive controlpivlow aspect ratio cylindervortexwakewavelet transform |
| spellingShingle | Hiroka RINOSHIKA Akira RINOSHIKA Shun FUJIMOTO Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole Journal of Fluid Science and Technology flow controlling hole passive control piv low aspect ratio cylinder vortex wake wavelet transform |
| title | Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole |
| title_full | Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole |
| title_fullStr | Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole |
| title_full_unstemmed | Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole |
| title_short | Passive control on flow structure around a wall-mounted low aspect ratio circular cylinder by using an inclined hole |
| title_sort | passive control on flow structure around a wall mounted low aspect ratio circular cylinder by using an inclined hole |
| topic | flow controlling hole passive control piv low aspect ratio cylinder vortex wake wavelet transform |
| url | https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0006/_pdf/-char/en |
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