New and improved hydraulic radius for channels of the second kind
The Manning’s equation is commonly used to calculate discharge and mean velocity of the uniform flows. According to experimental data, Manning’s equation with constant Manning’s coefficient overestimates the discharge of second-kind channels (channels with a closing top-width), under the partially f...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2015-09-01
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| Series: | Ain Shams Engineering Journal |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2090447915000295 |
| _version_ | 1818657351539884032 |
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| author | Ali R. Vatankhah S. Ghafari A. Mahdavi Mazdeh |
| author_facet | Ali R. Vatankhah S. Ghafari A. Mahdavi Mazdeh |
| author_sort | Ali R. Vatankhah |
| collection | DOAJ |
| description | The Manning’s equation is commonly used to calculate discharge and mean velocity of the uniform flows. According to experimental data, Manning’s equation with constant Manning’s coefficient overestimates the discharge of second-kind channels (channels with a closing top-width), under the partially full flow. This problem can be solved by altering the Manning’s coefficient depending on the relative flow depth or changing the definition of the conventional hydraulic radius, that is, flow area divided by the wetted perimeter. Since, Manning’s coefficient theoretically depends only on the materials of the wall, so it seems that the second method is preferable.
In current research a new and improved definition of hydraulic radius for closed conduits flowing partially full, is presented. This definition is efficient enough and provides powerful tool to determine the channel discharge and friction slope of uniform flow via Manning’s equation. |
| first_indexed | 2024-12-17T03:40:06Z |
| format | Article |
| id | doaj.art-92553d9bd82f40438de23730d0b26477 |
| institution | Directory Open Access Journal |
| issn | 2090-4479 |
| language | English |
| last_indexed | 2024-12-17T03:40:06Z |
| publishDate | 2015-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ain Shams Engineering Journal |
| spelling | doaj.art-92553d9bd82f40438de23730d0b264772022-12-21T22:05:01ZengElsevierAin Shams Engineering Journal2090-44792015-09-016376777310.1016/j.asej.2015.02.003New and improved hydraulic radius for channels of the second kindAli R. Vatankhah0S. Ghafari1A. Mahdavi Mazdeh2Department of Irrigation and Reclamation Engineering, University College of Agriculture and Natural Resources, University of Tehran, P.O. Box 4111, Karaj 31587-77871, IranDepartment of Water Structures Engineering, Bualisina University, Hamedan, IranDepartment of Water Engineering, Imam Khomeini International University, Qazvin, IranThe Manning’s equation is commonly used to calculate discharge and mean velocity of the uniform flows. According to experimental data, Manning’s equation with constant Manning’s coefficient overestimates the discharge of second-kind channels (channels with a closing top-width), under the partially full flow. This problem can be solved by altering the Manning’s coefficient depending on the relative flow depth or changing the definition of the conventional hydraulic radius, that is, flow area divided by the wetted perimeter. Since, Manning’s coefficient theoretically depends only on the materials of the wall, so it seems that the second method is preferable. In current research a new and improved definition of hydraulic radius for closed conduits flowing partially full, is presented. This definition is efficient enough and provides powerful tool to determine the channel discharge and friction slope of uniform flow via Manning’s equation.http://www.sciencedirect.com/science/article/pii/S2090447915000295Manning’s equationRoughness coefficientNew hydraulic radiusCircular cross-sectionHorseshoe cross-sectionSecond kind channels |
| spellingShingle | Ali R. Vatankhah S. Ghafari A. Mahdavi Mazdeh New and improved hydraulic radius for channels of the second kind Ain Shams Engineering Journal Manning’s equation Roughness coefficient New hydraulic radius Circular cross-section Horseshoe cross-section Second kind channels |
| title | New and improved hydraulic radius for channels of the second kind |
| title_full | New and improved hydraulic radius for channels of the second kind |
| title_fullStr | New and improved hydraulic radius for channels of the second kind |
| title_full_unstemmed | New and improved hydraulic radius for channels of the second kind |
| title_short | New and improved hydraulic radius for channels of the second kind |
| title_sort | new and improved hydraulic radius for channels of the second kind |
| topic | Manning’s equation Roughness coefficient New hydraulic radius Circular cross-section Horseshoe cross-section Second kind channels |
| url | http://www.sciencedirect.com/science/article/pii/S2090447915000295 |
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