The wake of falling disks at low Reynolds numbers

IMR OpenIR

	The wake of falling disks at low Reynolds numbers
其他题名	The wake of falling disks at low Reynolds numbers
	Zhong HongJie 1; Lee CunBiao 2
	2012
发表期刊	ACTA MECHANICA SINICA
ISSN	0567-7718
卷号	28 期号:2 页码:367-371
摘要	We visualized the wake structure of circular disks falling vertically in quiescent water. The evolution of the wake was shown to be similar to the flow patterns behind a fixed disk. The Reynolds number, Re = Ud/nu, is in the range of 40 - 200. With the ascension of Reynolds numbers, a regular bifurcation occurred at the first critical Reynolds number Re-c1, leading to a transition from an axisymmetric wake structure to a plane symmetric one; A Hopf bifurcation took place at the second critical Reynolds number Re-c2, as the wake structure became unsteady. Plane symmetry of the wake structure was first lost as periodic vortex shedding appeared, but recovered at higher Reynolds number. The difference between the two critical Reynolds numbers was found to be shape-dependent, as we compared our results for thin discs with those for other falling bodies, such as spheres and cones. This observation could be understood in terms of the instability mechanism of the vortical structure.
其他摘要	We visualized the wake structure of circular disks falling vertically in quiescent water.The evolution of the wake was shown to be similar to the flow patterns behind a fixed disk.The Reynolds number,Re = Ud/ν,is in the range of 40 200.With the ascension of Reynolds numbers,a regular bifurcation occurred at the first critical Reynolds number Re c 1,leading to a transition from an axisymmetric wake structure to a plane symmetric one;A Hopf bifurcation took place at the second critical Reynolds number Re c 2,as the wake structure became unsteady.Plane symmetry of the wake structure was first lost as periodic vortex shedding appeared,but recovered at higher Reynolds number.The difference between the two critical Reynolds numbers was found to be shape-dependent,as we compared our results for thin discs with those for other falling bodies,such as spheres and cones.This observation could be understood in terms of the instability mechanism of the vortical structure.
关键词	SPHERE TRANSITION STEADY FLOW INSTABILITY DYNAMICS BODIES Flow visualization Transition Wake
收录类别	CSCD
语种	英语
资助项目	[National Natural Science Fundation of China] ; [National Climb-B Plan] ; [National Foundation for Distinguished Young Scholar of China] ; [Science Fund for Creative Research Groups]
CSCD记录号	CSCD:4535459
引用统计	被引频次：2[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/157325
专题	中国科学院金属研究所
作者单位	1.中国科学院金属研究所 2.北京大学
推荐引用方式 GB/T 7714	Zhong HongJie,Lee CunBiao. The wake of falling disks at low Reynolds numbers[J]. ACTA MECHANICA SINICA,2012,28(2):367-371.
APA	Zhong HongJie,&Lee CunBiao.(2012).The wake of falling disks at low Reynolds numbers.ACTA MECHANICA SINICA,28(2),367-371.
MLA	Zhong HongJie,et al."The wake of falling disks at low Reynolds numbers".ACTA MECHANICA SINICA 28.2(2012):367-371.