Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint
Based on the two-dimensional hydrodynamic model of the finite volume method and structured multigrid, the flow characteristics around a square cylinder with boundary constraint are analysed. The gap ratio <i>G</i>/<i>D</i> (G is the distance from the cylinder to the channel b...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/15/8/1507 |
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| author | Zhun Xu Shiqiang Wu Xiufeng Wu Wanyun Xue Fangfang Wang Ang Gao Weile Zhang |
| author_facet | Zhun Xu Shiqiang Wu Xiufeng Wu Wanyun Xue Fangfang Wang Ang Gao Weile Zhang |
| author_sort | Zhun Xu |
| collection | DOAJ |
| description | Based on the two-dimensional hydrodynamic model of the finite volume method and structured multigrid, the flow characteristics around a square cylinder with boundary constraint are analysed. The gap ratio <i>G</i>/<i>D</i> (G is the distance from the cylinder to the channel boundary, and D is the side length of the square cylinder) does not change the four flow patterns. Under the laminar vortex street phase, the boundary constraint only reduces the scale of the vortices. The vortex centres are pressed toward the boundaries of the channel, and a low velocity zone is formed near the boundary, but the law of vorticity attenuation along the flow direction is not changed. The flow pattern classification map shows that the boundary constraint increases the Reynolds number required to generate the turbulence flow pattern, and the range of the Reynolds number in the flow pattern of the laminar vortex street has a maximum increase range. The correlation between the time-averaged drag coefficient or the vortex shedding frequency and Reynolds number under different gap ratios indicates that the resistance of the square cylinder and the vortex shedding frequency increase accordingly with the strengthening of the boundary constraint. When <i>G</i>/<i>D</i> < 3.5, the increase is particularly obvious. Meanwhile, the correlation characteristics between the resistance or the vortex shedding frequency of the square cylinder and the Reynolds number are unrelated to the boundary constraint strength. |
| first_indexed | 2024-03-11T04:25:54Z |
| format | Article |
| id | doaj.art-2781bcdb18d147a0bb8f2a2535b770c3 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-11T04:25:54Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-2781bcdb18d147a0bb8f2a2535b770c32023-11-17T21:48:09ZengMDPI AGWater2073-44412023-04-01158150710.3390/w15081507Analysis of Flow Characteristics around a Square Cylinder with Boundary ConstraintZhun Xu0Shiqiang Wu1Xiufeng Wu2Wanyun Xue3Fangfang Wang4Ang Gao5Weile Zhang6State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210098, ChinaBased on the two-dimensional hydrodynamic model of the finite volume method and structured multigrid, the flow characteristics around a square cylinder with boundary constraint are analysed. The gap ratio <i>G</i>/<i>D</i> (G is the distance from the cylinder to the channel boundary, and D is the side length of the square cylinder) does not change the four flow patterns. Under the laminar vortex street phase, the boundary constraint only reduces the scale of the vortices. The vortex centres are pressed toward the boundaries of the channel, and a low velocity zone is formed near the boundary, but the law of vorticity attenuation along the flow direction is not changed. The flow pattern classification map shows that the boundary constraint increases the Reynolds number required to generate the turbulence flow pattern, and the range of the Reynolds number in the flow pattern of the laminar vortex street has a maximum increase range. The correlation between the time-averaged drag coefficient or the vortex shedding frequency and Reynolds number under different gap ratios indicates that the resistance of the square cylinder and the vortex shedding frequency increase accordingly with the strengthening of the boundary constraint. When <i>G</i>/<i>D</i> < 3.5, the increase is particularly obvious. Meanwhile, the correlation characteristics between the resistance or the vortex shedding frequency of the square cylinder and the Reynolds number are unrelated to the boundary constraint strength.https://www.mdpi.com/2073-4441/15/8/1507flow around a square cylinderboundary constraintwake flow patternresistance strengthvortices shedding frequency |
| spellingShingle | Zhun Xu Shiqiang Wu Xiufeng Wu Wanyun Xue Fangfang Wang Ang Gao Weile Zhang Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint Water flow around a square cylinder boundary constraint wake flow pattern resistance strength vortices shedding frequency |
| title | Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint |
| title_full | Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint |
| title_fullStr | Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint |
| title_full_unstemmed | Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint |
| title_short | Analysis of Flow Characteristics around a Square Cylinder with Boundary Constraint |
| title_sort | analysis of flow characteristics around a square cylinder with boundary constraint |
| topic | flow around a square cylinder boundary constraint wake flow pattern resistance strength vortices shedding frequency |
| url | https://www.mdpi.com/2073-4441/15/8/1507 |
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