Wall-proximity effects on strouhal number for the circular cylinder in a shear flow | |
Liu Y(刘艳); Liu J(刘俊); Gao FP(高福平) | |
2021 | |
会议日期 | 20 June 2021 到 25 June 2021 |
会议地点 | Virtual, Online |
关键词 | Circular cylinder Particle Image Velocimetry (PIV) Shear flow Strouhal number Vortex shedding Wall proximity effects |
英文摘要 | Strouhal number is an essential dimensionless quantity for characterizing the vortex shedding frequency of the flow around a bluff body. In this study, the Strouhal number for a near-wall circular cylinder fully immerged in a shear flow was experimentally investigated within the subcritical Reynolds number range. The examined gap-to-diameter ratios (e/D) are in the range of 0.10 ~ 2.0. The velocity fluctuations of the lee-wake and the flow visualization were measured with an Acoustic Doppler Velocimeter and the Particle Image Velocimetry system, respectively. The wall-proximity effects on the vortex shedding and the corresponding Strouhal number (St) were investigated experimentally. Although the regular Kármán-like vortex-shedding can be suppressed for e/D 0.30, the power spectra for the velocity fluctuations in the lee-wake indicate that the characteristic frequency can still be well identified. The experimental results indicate that St increases with the decrease of e/D to a maximum value at e/D = 0.40; and the maximum of St is approximately 15 percent larger than that under wall-free condition. Broadband spectrum phenomenon was observed under the very-small e/D conditions (i.e., e/D 0.20). The shear parameter (K) of the shear flow is proposed, and its explicit expression is derived for characterizing the wall-proximity. The relationship between the Strouhal number St and e/D (or K) is finally established for 0.10 e/D 2.0. © 2021 by the International Society of Offshore and Polar Engineers (ISOPE). |
会议录 | Proceedings of the International Offshore and Polar Engineering Conference |
语种 | 英语 |
内容类型 | 会议论文 |
源URL | [http://dspace.imech.ac.cn/handle/311007/87799] |
专题 | 力学研究所_流固耦合系统力学重点实验室(2012-) |
作者单位 | 1.School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China 2.Key Laboratory for Mechanics in Fluid Solid Coupling Systems, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China |
推荐引用方式 GB/T 7714 | Liu Y,Liu J,Gao FP. Wall-proximity effects on strouhal number for the circular cylinder in a shear flow[C]. 见:. Virtual, Online. 20 June 2021 到 25 June 2021. |
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