Triggering mechanics for transverse vibrations of a circular cylinder in a shear flow: Wall-proximity effects

doi:10.1016/j.jfluidstructs.2021.103423

CORC > 力学研究所 > 中国科学院力学研究所 > 流固耦合系统力学重点实验室(2012-)

	Triggering mechanics for transverse vibrations of a circular cylinder in a shear flow: Wall-proximity effects
	Liu J(刘俊); Gao FP(高福平)
刊名	JOURNAL OF FLUIDS AND STRUCTURES
	2022-01
卷号	108 页码:103423
关键词	Vortex-induced vibrations Critical reduced velocity Wall-proximity effects Vortex-shedding Shear flow Circular cylinder
ISSN号	0889-9746
DOI	10.1016/j.jfluidstructs.2021.103423
英文摘要	Vortex-Induced Vibrations (VIVs) of a near-wall cylinder involve complex interactions between the structure and the boundary layers in the shear flow. Based on dimensional analyses, the wall-proximity effects on the triggering of transverse VIVs of a circular cylinder are physically investigated with flume observations. An accessorial low structural-damping VIV simulation device was developed and an upward-illumination Particle Image Velocimetry (PIV) system was employed in the physical modeling. Although the regular Karman-like vortex-shedding could be suppressed for small gapto-diameter ratios (e.g., e/D < 0.40) as reported in previous studies, the present power spectral analyses on the velocity fluctuations in the lee-wake indicate that the characteristic frequency can still be well identified, which could further trigger the vibrations of a low mass-damping cylinder. PIV measurements show that, as the cylinder approaches the bottom, the asymmetry of swirling-strengths in the lee-wake gets more remarkable, and the values of Strouhal number increase correspondingly. Four typical stages can be identified in the process of the vibration being triggered under the wall-free condition, including (a) the fully-stationary, (b) the intermittent-vibrating, (c) the sharp-jump, and (d) the upper-branch vibration stages. But, for e/D <= 0.20, the intermittent-vibrating stage disappeared. During the sharp-jump stage, the peak jump-amplitude decreases dramatically as the cylinder approaches the bottom, which has negative correlation with the vibration frequency. The effects of the swirling-strength attenuation and the downward collisions on the vibration responses are discussed. The relationship between critical reduced velocity Vr(cr) and e/D is finally established by fitting the experimental results. It is indicated that the wall-proximity effects could be significant and should be taken into account while evaluating the critical velocity for triggering transverse vibrations of the near-wall cylinder in the engineering practices. (C) 2021 Elsevier Ltd. All rights reserved.
学科主题	Engineering, Mechanical ; Mechanics
分类号	二类
语种	英语
WOS记录号	WOS:000722315100004
资助机构	National Natural Science Foundation of China [11825205, 12061160463] ; Strategic Priority Research Program (Type-B) of Chinese Academy of Sciences [XDB22030000]
其他责任者	Gao, FP (corresponding author), Chinese Acad Sci, Inst Mech, Key Lab Mech Fluid Solid Coupling Syst, Beijing 100190, Peoples R China.
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/90182]
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.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Inst Mech, Key Lab Mech Fluid Solid Coupling Syst, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Liu J,Gao FP. Triggering mechanics for transverse vibrations of a circular cylinder in a shear flow: Wall-proximity effects[J]. JOURNAL OF FLUIDS AND STRUCTURES,2022,108:103423.
APA	刘俊,&高福平.(2022).Triggering mechanics for transverse vibrations of a circular cylinder in a shear flow: Wall-proximity effects.JOURNAL OF FLUIDS AND STRUCTURES,108,103423.
MLA	刘俊,et al."Triggering mechanics for transverse vibrations of a circular cylinder in a shear flow: Wall-proximity effects".JOURNAL OF FLUIDS AND STRUCTURES 108(2022):103423.