Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway
A numerical study is conducted for converging stepped spillways with various spillway slopes, sidewall convergence and flow discharges to understand the influences of converging sidewalls on skimming flows. Compared with the traditional uniform-width stepped spillway, the converging sidewall changes...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/15/7868 |
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| author | Yuling Chen Guangyuan Liu Shangtuo Qian Hui Xu Jiangang Feng Xiaosheng Wang |
| author_facet | Yuling Chen Guangyuan Liu Shangtuo Qian Hui Xu Jiangang Feng Xiaosheng Wang |
| author_sort | Yuling Chen |
| collection | DOAJ |
| description | A numerical study is conducted for converging stepped spillways with various spillway slopes, sidewall convergence and flow discharges to understand the influences of converging sidewalls on skimming flows. Compared with the traditional uniform-width stepped spillway, the converging sidewall changes the skimming flow features by generating standing waves on the free-surface, curving the mainstream streamlines and squeezing and distorting the bottom rotations. For free-surface, mainstream and bottom rotations, the width of disturbed regions by the converging sidewall varies, with that for bottom rotations being 1.5 times that for mainstream and 3 times that for free-surface. The variation rules of disturbed region widths along the spillway are obtained, and the maximum widths increase as the convergence angle and incoming flow discharge increase, and the spillway slope decreases. Three equations are established for predicting the maximum widths of disturbed regions for free-surface, mainstream and bottom rotations of skimming flow. Since the disturbed region of skimming flow generated by the converging sidewall is characterized by strong standing waves, high flow velocity and low air concentration, appropriate engineering measurements should be taken for the disturbed region to meet the challenges to overtopping, energy dissipation and cavitation control. |
| first_indexed | 2024-03-09T12:45:53Z |
| format | Article |
| id | doaj.art-766585933d12419fae9bb7d162db6b38 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T12:45:53Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-766585933d12419fae9bb7d162db6b382023-11-30T22:11:56ZengMDPI AGApplied Sciences2076-34172022-08-011215786810.3390/app12157868Effects of Converging Sidewalls on Skimming Flow over Converging Stepped SpillwayYuling Chen0Guangyuan Liu1Shangtuo Qian2Hui Xu3Jiangang Feng4Xiaosheng Wang5College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, ChinaCollege of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, ChinaCollege of Agricultural Science and Engineering, Hohai University, Nanjing 210098, ChinaCollege of Agricultural Science and Engineering, Hohai University, Nanjing 210098, ChinaCollege of Agricultural Science and Engineering, Hohai University, Nanjing 210098, ChinaCollege of Agricultural Science and Engineering, Hohai University, Nanjing 210098, ChinaA numerical study is conducted for converging stepped spillways with various spillway slopes, sidewall convergence and flow discharges to understand the influences of converging sidewalls on skimming flows. Compared with the traditional uniform-width stepped spillway, the converging sidewall changes the skimming flow features by generating standing waves on the free-surface, curving the mainstream streamlines and squeezing and distorting the bottom rotations. For free-surface, mainstream and bottom rotations, the width of disturbed regions by the converging sidewall varies, with that for bottom rotations being 1.5 times that for mainstream and 3 times that for free-surface. The variation rules of disturbed region widths along the spillway are obtained, and the maximum widths increase as the convergence angle and incoming flow discharge increase, and the spillway slope decreases. Three equations are established for predicting the maximum widths of disturbed regions for free-surface, mainstream and bottom rotations of skimming flow. Since the disturbed region of skimming flow generated by the converging sidewall is characterized by strong standing waves, high flow velocity and low air concentration, appropriate engineering measurements should be taken for the disturbed region to meet the challenges to overtopping, energy dissipation and cavitation control.https://www.mdpi.com/2076-3417/12/15/7868bottom rotationsconverging sidewalldisturbed regionfree-surfacemainstreamstanding wave |
| spellingShingle | Yuling Chen Guangyuan Liu Shangtuo Qian Hui Xu Jiangang Feng Xiaosheng Wang Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway Applied Sciences bottom rotations converging sidewall disturbed region free-surface mainstream standing wave |
| title | Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway |
| title_full | Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway |
| title_fullStr | Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway |
| title_full_unstemmed | Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway |
| title_short | Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway |
| title_sort | effects of converging sidewalls on skimming flow over converging stepped spillway |
| topic | bottom rotations converging sidewall disturbed region free-surface mainstream standing wave |
| url | https://www.mdpi.com/2076-3417/12/15/7868 |
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