Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect
The experimental study of vortex induced vibration needs to be carried out in water tunnel, but in previous associated simulation work, the water tunnel was treated as an infinite flow field in the depth direction with the effect of the free surface neglected. In the paper, the dynamic characteristi...
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| Format: | Article |
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MDPI AG
2020-02-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/13/4/907 |
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| author | Dahai Zhang Lei Feng Hao Yang Tianjiao Li Hai Sun |
| author_facet | Dahai Zhang Lei Feng Hao Yang Tianjiao Li Hai Sun |
| author_sort | Dahai Zhang |
| collection | DOAJ |
| description | The experimental study of vortex induced vibration needs to be carried out in water tunnel, but in previous associated simulation work, the water tunnel was treated as an infinite flow field in the depth direction with the effect of the free surface neglected. In the paper, the dynamic characteristics and physical mechanisms of a passive turbulence control (PTC) cylinder in a flow field with a free surface is studied, and the combined technique of a volume of fluid (VOF) method and vortex-induced vibration (VIV) was realized. In the range of Reynolds number studied in this paper (3.5 × 10<sup>4</sup> ≤ Re ≤ 7.0 × 10<sup>4</sup>), the dynamic parameters (lift and drag coefficients), vortex structures, VIV response (amplitude and frequency ratios), and energy harvesting characteristics of a PTC cylinder under different flow conditions were obtained. The study found that: (1) the shear layer was made more unstable behind the cylinder by the free surface, which made it quicker to reach periodic stability, and the asymmetry shortened the initial stage of vibration of the oscillator, which made it easier to produce dynamic control of the motion of the oscillator; (2) the presence of the free surface only affected the positive amplitude ratio, but had almost no effect on the negative amplitude ratio; (3) the frequency ratio in the free surface flow was closer to the experimental data; (4) the presence of the free surface did not affect the detached vortex pattern in the flow around the stationary cylinder, but in the VIV, the lower the free surface height Z, the more vortices that were shed from the moving cylinder. |
| first_indexed | 2024-04-13T07:57:32Z |
| format | Article |
| id | doaj.art-fc0362d26b7b41beb8e738202e6af439 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-13T07:57:32Z |
| publishDate | 2020-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-fc0362d26b7b41beb8e738202e6af4392022-12-22T02:55:22ZengMDPI AGEnergies1996-10732020-02-0113490710.3390/en13040907en13040907Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface EffectDahai Zhang0Lei Feng1Hao Yang2Tianjiao Li3Hai Sun4College of New Energy, China University of Petroleum (East China), Qingdao 266580, ChinaCollege of New Energy, China University of Petroleum (East China), Qingdao 266580, ChinaCollege of New Energy, China University of Petroleum (East China), Qingdao 266580, ChinaCollege of New Energy, China University of Petroleum (East China), Qingdao 266580, ChinaCollege of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, ChinaThe experimental study of vortex induced vibration needs to be carried out in water tunnel, but in previous associated simulation work, the water tunnel was treated as an infinite flow field in the depth direction with the effect of the free surface neglected. In the paper, the dynamic characteristics and physical mechanisms of a passive turbulence control (PTC) cylinder in a flow field with a free surface is studied, and the combined technique of a volume of fluid (VOF) method and vortex-induced vibration (VIV) was realized. In the range of Reynolds number studied in this paper (3.5 × 10<sup>4</sup> ≤ Re ≤ 7.0 × 10<sup>4</sup>), the dynamic parameters (lift and drag coefficients), vortex structures, VIV response (amplitude and frequency ratios), and energy harvesting characteristics of a PTC cylinder under different flow conditions were obtained. The study found that: (1) the shear layer was made more unstable behind the cylinder by the free surface, which made it quicker to reach periodic stability, and the asymmetry shortened the initial stage of vibration of the oscillator, which made it easier to produce dynamic control of the motion of the oscillator; (2) the presence of the free surface only affected the positive amplitude ratio, but had almost no effect on the negative amplitude ratio; (3) the frequency ratio in the free surface flow was closer to the experimental data; (4) the presence of the free surface did not affect the detached vortex pattern in the flow around the stationary cylinder, but in the VIV, the lower the free surface height Z, the more vortices that were shed from the moving cylinder.https://www.mdpi.com/1996-1073/13/4/907ptcvivfree surfaceenergy harvesting |
| spellingShingle | Dahai Zhang Lei Feng Hao Yang Tianjiao Li Hai Sun Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect Energies ptc viv free surface energy harvesting |
| title | Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect |
| title_full | Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect |
| title_fullStr | Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect |
| title_full_unstemmed | Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect |
| title_short | Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect |
| title_sort | vortex induced vibration characteristics of a ptc cylinder with a free surface effect |
| topic | ptc viv free surface energy harvesting |
| url | https://www.mdpi.com/1996-1073/13/4/907 |
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