Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios
Vertical drops are widely implemented in hydraulic structures such as irrigation canals, wastewater collection systems, and stepped spillways to dissipate flow kinetic energy while enhancing aeration and promoting dissolved oxygen levels. Depending on local topography, these structures serve to redu...
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| Format: | Article |
| Language: | English |
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Razi University
2025-06-01
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| Series: | Journal of Applied Research in Water and Wastewater |
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| Online Access: | https://arww.razi.ac.ir/article_3753_29e54efeece16f918cea9ea0fe15ed61.pdf |
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| author | Hossein Shahin Afshin Eghbalzadeh Mitra Javan |
| author_facet | Hossein Shahin Afshin Eghbalzadeh Mitra Javan |
| author_sort | Hossein Shahin |
| collection | DOAJ |
| description | Vertical drops are widely implemented in hydraulic structures such as irrigation canals, wastewater collection systems, and stepped spillways to dissipate flow kinetic energy while enhancing aeration and promoting dissolved oxygen levels. Depending on local topography, these structures serve to reduce the kinetic energy of falling water and to regulate the flow velocity within canals and irrigation networks. In this study, a three-dimensional numerical simulation was performed to investigate the flow pattern over a vertical drop featuring a sudden contraction under various contraction ratios. The simulation employed the RNG k-ε turbulence model in conjunction with the volume of fluid (VOF) method to capture free surface dynamics. The computational model was validated against experimental data, yielding acceptable levels of accuracy based on average percentage error (APE) and root mean square error (RMSE) metrics. Moreover, results indicate that a reduction in the contraction ratio leads to an increase in the falling jet thickness and hydraulic jump height, accompanied by a decrease in the water jet length. These changes promote enhanced energy dissipation, which is critical for reducing the kinetic energy of the flow in hydraulic structures such as irrigation canals, wastewater collection systems, and spillways. The findings suggest that optimizing the contraction ratio is an effective design parameter for improving energy dissipation efficiency and overall hydraulic performance. |
| format | Article |
| id | doaj-art-2adfc704c2e044c8b5a819053ee907e6 |
| institution | DOAJ |
| issn | 2476-6283 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Razi University |
| record_format | Article |
| series | Journal of Applied Research in Water and Wastewater |
| spelling | doaj-art-2adfc704c2e044c8b5a819053ee907e62025-08-20T03:01:41ZengRazi UniversityJournal of Applied Research in Water and Wastewater2476-62832025-06-01121586310.22126/arww.2025.11775.13563753Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratiosHossein Shahin0Afshin Eghbalzadeh1Mitra Javan2Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran.Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran.Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran.Vertical drops are widely implemented in hydraulic structures such as irrigation canals, wastewater collection systems, and stepped spillways to dissipate flow kinetic energy while enhancing aeration and promoting dissolved oxygen levels. Depending on local topography, these structures serve to reduce the kinetic energy of falling water and to regulate the flow velocity within canals and irrigation networks. In this study, a three-dimensional numerical simulation was performed to investigate the flow pattern over a vertical drop featuring a sudden contraction under various contraction ratios. The simulation employed the RNG k-ε turbulence model in conjunction with the volume of fluid (VOF) method to capture free surface dynamics. The computational model was validated against experimental data, yielding acceptable levels of accuracy based on average percentage error (APE) and root mean square error (RMSE) metrics. Moreover, results indicate that a reduction in the contraction ratio leads to an increase in the falling jet thickness and hydraulic jump height, accompanied by a decrease in the water jet length. These changes promote enhanced energy dissipation, which is critical for reducing the kinetic energy of the flow in hydraulic structures such as irrigation canals, wastewater collection systems, and spillways. The findings suggest that optimizing the contraction ratio is an effective design parameter for improving energy dissipation efficiency and overall hydraulic performance.https://arww.razi.ac.ir/article_3753_29e54efeece16f918cea9ea0fe15ed61.pdfvertical dropcontraction ratiofalling jetfree surfacesudden contraction |
| spellingShingle | Hossein Shahin Afshin Eghbalzadeh Mitra Javan Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios Journal of Applied Research in Water and Wastewater vertical drop contraction ratio falling jet free surface sudden contraction |
| title | Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| title_full | Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| title_fullStr | Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| title_full_unstemmed | Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| title_short | Numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| title_sort | numerical investigation of flow field characteristics over vertical drops with sudden contraction for different contraction ratios |
| topic | vertical drop contraction ratio falling jet free surface sudden contraction |
| url | https://arww.razi.ac.ir/article_3753_29e54efeece16f918cea9ea0fe15ed61.pdf |
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