Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways
Siphon-shaft spillways can discharge large amounts of water down to the crest level in a narrow reservoir thanks to the siphonic pressures. However, cavitational pressures in the siphon-shaft limit the operating head of these spillways. An enlargement at the shaft mouth can reduce the vacuum pressur...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IWA Publishing
2023-06-01
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| Series: | H2Open Journal |
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| Online Access: | http://h2oj.iwaponline.com/content/6/2/256 |
| _version_ | 1797783022508965888 |
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| author | M. Cihan Aydin Ali Emre Ulu |
| author_facet | M. Cihan Aydin Ali Emre Ulu |
| author_sort | M. Cihan Aydin |
| collection | DOAJ |
| description | Siphon-shaft spillways can discharge large amounts of water down to the crest level in a narrow reservoir thanks to the siphonic pressures. However, cavitational pressures in the siphon-shaft limit the operating head of these spillways. An enlargement at the shaft mouth can reduce the vacuum pressures and velocities within the siphonic flows, thereby removing the risk of cavitation occurring. In this study, four different enlarging shaft profiles with various coning angles of 0°, 10°, 15°, and 20° were applied to a siphon-shaft spillway model to eliminate cavitation pressures in the shaft. These models are analyzed in three dimensions by computational fluid dynamics based on the RANS turbulence model coupled with the Volume of Fluid (VOF) method to simulate fluid motion. The numerical uncertainties of the simulation were calibrated with some experimental results and techniques in the literature. The results showed that the enlargement in the shaft mouth with a conical profile significantly decreased the vacuum pressures and velocities in the siphon-shaft. Thus, the use of conical profiles considerably reduced the cavitation numbers along the shaft surface and increased the discharge performance by about 11%.
HIGHLIGHTS
A new methodological and hydraulic approach to siphon-shaft weirs is presented.;
The models applied in the study significantly reduced the cavitation pressure.;
With the applied models, the spillway performance of the siphon-shaft weirs has been significantly improved.; |
| first_indexed | 2024-03-13T00:20:13Z |
| format | Article |
| id | doaj.art-4366452e0ed043ac938ef5a0a756d07e |
| institution | Directory Open Access Journal |
| issn | 2616-6518 |
| language | English |
| last_indexed | 2024-03-13T00:20:13Z |
| publishDate | 2023-06-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | H2Open Journal |
| spelling | doaj.art-4366452e0ed043ac938ef5a0a756d07e2023-07-11T15:35:21ZengIWA PublishingH2Open Journal2616-65182023-06-016225626710.2166/h2oj.2023.068068Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillwaysM. Cihan Aydin0Ali Emre Ulu1 Department of Civil Engineering, Bitlis Eren University, Bitlis 13100, Turkey Department of Civil Engineering, Bitlis Eren University, Bitlis 13100, Turkey Siphon-shaft spillways can discharge large amounts of water down to the crest level in a narrow reservoir thanks to the siphonic pressures. However, cavitational pressures in the siphon-shaft limit the operating head of these spillways. An enlargement at the shaft mouth can reduce the vacuum pressures and velocities within the siphonic flows, thereby removing the risk of cavitation occurring. In this study, four different enlarging shaft profiles with various coning angles of 0°, 10°, 15°, and 20° were applied to a siphon-shaft spillway model to eliminate cavitation pressures in the shaft. These models are analyzed in three dimensions by computational fluid dynamics based on the RANS turbulence model coupled with the Volume of Fluid (VOF) method to simulate fluid motion. The numerical uncertainties of the simulation were calibrated with some experimental results and techniques in the literature. The results showed that the enlargement in the shaft mouth with a conical profile significantly decreased the vacuum pressures and velocities in the siphon-shaft. Thus, the use of conical profiles considerably reduced the cavitation numbers along the shaft surface and increased the discharge performance by about 11%. HIGHLIGHTS A new methodological and hydraulic approach to siphon-shaft weirs is presented.; The models applied in the study significantly reduced the cavitation pressure.; With the applied models, the spillway performance of the siphon-shaft weirs has been significantly improved.;http://h2oj.iwaponline.com/content/6/2/256cavitation controlcfdcomputational fluid dynamicslinear enlargementshaft profilesiphon-shaft spillway |
| spellingShingle | M. Cihan Aydin Ali Emre Ulu Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways H2Open Journal cavitation control cfd computational fluid dynamics linear enlargement shaft profile siphon-shaft spillway |
| title | Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways |
| title_full | Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways |
| title_fullStr | Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways |
| title_full_unstemmed | Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways |
| title_short | Effects of a conical enlarging shaft on hydraulic performances of siphon-shaft spillways |
| title_sort | effects of a conical enlarging shaft on hydraulic performances of siphon shaft spillways |
| topic | cavitation control cfd computational fluid dynamics linear enlargement shaft profile siphon-shaft spillway |
| url | http://h2oj.iwaponline.com/content/6/2/256 |
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