Analysis of upper and lower nappe profiles of large orifice for the design of bottom and roof profiles of high head orifice spillway
| Autor: | Shafqat Hussain Bhatti, Habib Ur Rehman, Muhammad Kaleem Sarwar, Muhammad Waqas Zaffar, Muhammad Awais Zafar, Muhammad Atiq Ur Rehman Tariq |
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| Jazyk: | angličtina |
| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | Aqua, Vol 73, Iss 3, Pp 674-687 (2024) |
| Druh dokumentu: | article |
| ISSN: | 2709-8028 2709-8036 |
| DOI: | 10.2166/aqua.2024.034 |
| Popis: | Large orifices are constructed for dams to release water and sediments from reservoirs. Such structures are called submerged spillways. Numerous studies have investigated discharge coefficient, velocity coefficient, and head loss coefficient of large orifices; however, the literature lacks data on the upper and lower nappes of the jets from these orifices. In the present experimental study, the upper and lower nappes are investigated up to 80 m head at different gate openings. The observed minor deviation between the lower nappe profile and trajectory profile equation suggests sensitivity to different factors. The significant role of the coefficient of velocity, averaging at 0.926, highlights its impact on minor deviation. Subsequently, the impact of the solid bottom profile on the discharge coefficient and upper nappe profile are also examined. The results show improvement in discharge coefficient of a sharp-edged large orifice, which increased from 0.69 to 0.74. The results also indicate that the upper nappe profiles and United States Bureau of Reclamation (USBR) profiles are similar. The improvement in the upper nappe profile indicates the significant role of the solid bottom profile, which consequently was found to be helpful in defining the roof profile of an orifice spillway. . HIGHLIGHTS Hydraulic analyses of lower and upper nappe profiles of sharp-edged large orifices.; Impact evaluation of a solid bottom profile on an upper nappe profile.; Hydraulic performance evaluation of solid bottom profile at various operational scenarios.; |
| Databáze: | Directory of Open Access Journals |
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