Experimental study on dam outlet works using a link-sleeve valve with air aspiration
In recent years, the importance of hydraulic power generation has further increased because of the movement toward decarbonization and the need to control floods in Japan. For this reason, demand for dam discharge valves has been increasing. However, it is necessary to improve the reliability of val...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2022-07-01
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| Series: | Mechanical Engineering Journal |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/mej/9/4/9_22-00065/_pdf/-char/en |
| _version_ | 1797985006743715840 |
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| author | Takafumi SHIMODA Takashi NOGUCHI Katsuya HIRATA Koichi YONEZAWA Takahiro SATO Keisuke MATSUBARA Atsushi NAGASE |
| author_facet | Takafumi SHIMODA Takashi NOGUCHI Katsuya HIRATA Koichi YONEZAWA Takahiro SATO Keisuke MATSUBARA Atsushi NAGASE |
| author_sort | Takafumi SHIMODA |
| collection | DOAJ |
| description | In recent years, the importance of hydraulic power generation has further increased because of the movement toward decarbonization and the need to control floods in Japan. For this reason, demand for dam discharge valves has been increasing. However, it is necessary to improve the reliability of valve systems due to their complicated two-phase flows. Therefore, in this study we attempt to apply a link-sleeve valve (LSV), which is usually used for public water supply, as a dam discharge valve. In general, to prevent cavitation erosion, vibration, and noise, air is injected into the downstream pipe of a dam discharge system. Since LSVs are designed to operate in a pressured water supply system, however, the characteristics of air‒water two-phase flows in LSVs have not been investigated. To clarify the characteristics of air entrainment by water jets in an LSV, experiments were conducted using a small-scale LSV model. The results showed that this entrainment is analogous to that which occurs with a jet pump or an ejector at a high water flow rate, while air suction behavior shows complicated characteristics at low water flow rates. This means that air entrainment occurs due to the water jet and that air reverse flow occurs due to the positive pressure gradient in the pipe at a high water flow rate. The present findings could be useful for improving the potential use of LSVs as a lower-maintenance alternative to dedicated dam discharge valves. |
| first_indexed | 2024-04-11T07:11:52Z |
| format | Article |
| id | doaj.art-07734e9e31e544bb8307fad3a7d3bb54 |
| institution | Directory Open Access Journal |
| issn | 2187-9745 |
| language | English |
| last_indexed | 2024-04-11T07:11:52Z |
| publishDate | 2022-07-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Mechanical Engineering Journal |
| spelling | doaj.art-07734e9e31e544bb8307fad3a7d3bb542022-12-22T04:38:08ZengThe Japan Society of Mechanical EngineersMechanical Engineering Journal2187-97452022-07-019422-0006522-0006510.1299/mej.22-00065mejExperimental study on dam outlet works using a link-sleeve valve with air aspirationTakafumi SHIMODA0Takashi NOGUCHI1Katsuya HIRATA2Koichi YONEZAWA3Takahiro SATO4Keisuke MATSUBARA5Atsushi NAGASE6Department of Mechanical Engineering, Doshisha UniversityDepartment of Mechanical Engineering, Doshisha UniversityDepartment of Mechanical Engineering, Doshisha UniversityCentral Research Institute of Electric Power IndustryCentral Research Institute of Electric Power IndustryKurimoto, LtdKurimoto, LtdIn recent years, the importance of hydraulic power generation has further increased because of the movement toward decarbonization and the need to control floods in Japan. For this reason, demand for dam discharge valves has been increasing. However, it is necessary to improve the reliability of valve systems due to their complicated two-phase flows. Therefore, in this study we attempt to apply a link-sleeve valve (LSV), which is usually used for public water supply, as a dam discharge valve. In general, to prevent cavitation erosion, vibration, and noise, air is injected into the downstream pipe of a dam discharge system. Since LSVs are designed to operate in a pressured water supply system, however, the characteristics of air‒water two-phase flows in LSVs have not been investigated. To clarify the characteristics of air entrainment by water jets in an LSV, experiments were conducted using a small-scale LSV model. The results showed that this entrainment is analogous to that which occurs with a jet pump or an ejector at a high water flow rate, while air suction behavior shows complicated characteristics at low water flow rates. This means that air entrainment occurs due to the water jet and that air reverse flow occurs due to the positive pressure gradient in the pipe at a high water flow rate. The present findings could be useful for improving the potential use of LSVs as a lower-maintenance alternative to dedicated dam discharge valves.https://www.jstage.jst.go.jp/article/mej/9/4/9_22-00065/_pdf/-char/envalvejet flowentrainmentair aspirationtwo-phase flowexperimental fluid dynamics (efd) |
| spellingShingle | Takafumi SHIMODA Takashi NOGUCHI Katsuya HIRATA Koichi YONEZAWA Takahiro SATO Keisuke MATSUBARA Atsushi NAGASE Experimental study on dam outlet works using a link-sleeve valve with air aspiration Mechanical Engineering Journal valve jet flow entrainment air aspiration two-phase flow experimental fluid dynamics (efd) |
| title | Experimental study on dam outlet works using a link-sleeve valve with air aspiration |
| title_full | Experimental study on dam outlet works using a link-sleeve valve with air aspiration |
| title_fullStr | Experimental study on dam outlet works using a link-sleeve valve with air aspiration |
| title_full_unstemmed | Experimental study on dam outlet works using a link-sleeve valve with air aspiration |
| title_short | Experimental study on dam outlet works using a link-sleeve valve with air aspiration |
| title_sort | experimental study on dam outlet works using a link sleeve valve with air aspiration |
| topic | valve jet flow entrainment air aspiration two-phase flow experimental fluid dynamics (efd) |
| url | https://www.jstage.jst.go.jp/article/mej/9/4/9_22-00065/_pdf/-char/en |
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