Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe
The fluctuating flow phenomena on a two-phase flow through a vertical sudden expansion pipe system are investigated experimentally and visually. The effect of the volumetric gas flow rate ratio within the range of bubbly flow is investigated. Simple flow control methods are proposed and tested in co...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2009-01-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/4/1/4_1_84/_pdf/-char/en |
| _version_ | 1819364497939234816 |
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| author | Alexandros VOUTSINAS Toshihiko SHAKOUCHI Koichi TSUJIMOTO Toshitake ANDO |
| author_facet | Alexandros VOUTSINAS Toshihiko SHAKOUCHI Koichi TSUJIMOTO Toshitake ANDO |
| author_sort | Alexandros VOUTSINAS |
| collection | DOAJ |
| description | The fluctuating flow phenomena on a two-phase flow through a vertical sudden expansion pipe system are investigated experimentally and visually. The effect of the volumetric gas flow rate ratio within the range of bubbly flow is investigated. Simple flow control methods are proposed and tested in comparison with the normal expansion case. The first method applies control by mounting a ring shaped obstacle downstream the expansion, and the second by mounting a step-ring just downstream. These two methods are based on a different control concept. The first is based on splitting the vortex region, thus decreasing its intensity, and the second on decreasing the overall generated vortex region length. In single-phase flow, only one dominant frequency is observed. However, when gas is induced, two dominant peaks appear and a tendency of the second peak to shift to lower frequency values when increasing the volumetric gas fraction is observed. When the flow control methods are applied, the fluctuation frequency is not affected, but the fluctuation amplitude decreases. From pressure distribution measurements under several flow conditions, it was confirmed that when the flow control methods are applied, drag reduction is achieved as well. |
| first_indexed | 2024-12-24T22:59:53Z |
| format | Article |
| id | doaj.art-c121647676644710b88dafeaa587bc40 |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-12-24T22:59:53Z |
| publishDate | 2009-01-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-c121647676644710b88dafeaa587bc402022-12-21T16:35:09ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582009-01-0141849410.1299/jfst.4.84jfstFluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion PipeAlexandros VOUTSINAS0Toshihiko SHAKOUCHI1Koichi TSUJIMOTO2Toshitake ANDO3Graduate School of Engineering, Mie UniversityGraduate School of Engineering, Mie UniversityGraduate School of Engineering, Mie UniversityGraduate School of Engineering, Mie UniversityThe fluctuating flow phenomena on a two-phase flow through a vertical sudden expansion pipe system are investigated experimentally and visually. The effect of the volumetric gas flow rate ratio within the range of bubbly flow is investigated. Simple flow control methods are proposed and tested in comparison with the normal expansion case. The first method applies control by mounting a ring shaped obstacle downstream the expansion, and the second by mounting a step-ring just downstream. These two methods are based on a different control concept. The first is based on splitting the vortex region, thus decreasing its intensity, and the second on decreasing the overall generated vortex region length. In single-phase flow, only one dominant frequency is observed. However, when gas is induced, two dominant peaks appear and a tendency of the second peak to shift to lower frequency values when increasing the volumetric gas fraction is observed. When the flow control methods are applied, the fluctuation frequency is not affected, but the fluctuation amplitude decreases. From pressure distribution measurements under several flow conditions, it was confirmed that when the flow control methods are applied, drag reduction is achieved as well.https://www.jstage.jst.go.jp/article/jfst/4/1/4_1_84/_pdf/-char/ensudden expansion pipebubbly flowfluctuating flowflow controldrag reduction |
| spellingShingle | Alexandros VOUTSINAS Toshihiko SHAKOUCHI Koichi TSUJIMOTO Toshitake ANDO Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe Journal of Fluid Science and Technology sudden expansion pipe bubbly flow fluctuating flow flow control drag reduction |
| title | Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe |
| title_full | Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe |
| title_fullStr | Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe |
| title_full_unstemmed | Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe |
| title_short | Fluctuating Phenomena and Flow Control of Bubbly Two-Phase Flow Through Sudden Expansion Pipe |
| title_sort | fluctuating phenomena and flow control of bubbly two phase flow through sudden expansion pipe |
| topic | sudden expansion pipe bubbly flow fluctuating flow flow control drag reduction |
| url | https://www.jstage.jst.go.jp/article/jfst/4/1/4_1_84/_pdf/-char/en |
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