Effect of perforation on flow past a conic cylinder at Re=100: wavy vortex and sign laws | |
Lin LM(林黎明); Zhong XF(钟兴福); Wu YX(吴应湘) | |
Source Publication | ACTA MECHANICA SINICA |
2018-10-01 | |
Volume | 34Issue:5Pages:812-829 |
ISSN | 0567-7718 |
Abstract | In order to find the intrinsic physical mechanism of the original Karman vortex wavily distorted across the span due to the introduction of three-dimensional (3-D) geometric disturbances, a flow past a peak-perforated conic shroud is numerically simulated at a Reynolds number of 100. Based on previous work by Meiburg and Lasheras (1988), the streamwise and vertical interactions with spanwise vortices are introduced and analyzed. Then vortex-shedding patterns in the near wake for different flow regimes are reinspected and illustrated from the view of these two interactions. Generally, in regime I, spanwise vortices are a little distorted due to the weak interaction. Then in regime II, spanwise vortices, even though curved obviously, are still shed synchronously with moderate streamwise and vertical interactions. But in regime III, violently wavy spanwise vortices in some vortex-shedding patterns, typically an Omega-type vortex, are mainly attributed to the strong vertical interactions, while other cases, such as multiple vortex-shedding patterns in sub-regime III-D, are resulted from complex streamwise and vertical interactions. A special phenomenon, spacial distribution of streamwise and vertical components of vorticity with specific signs in the near wake, is analyzed based on two models of streamwise and vertical vortices in explaining physical reasons of top and bottom shear layers wavily varied across the span. Then these two models and above two interactions are unified. Finally two sign laws are summarized: the first sign law for streamwise and vertical components of vorticity is positive in the upper shear layer, but negative in the lower shear layer, while the second sign law for three vorticity components is always negative in the wake. |
Keyword | Vortex-shedding pattern Flow control Vortex dynamics Conic disturbance Perforation Sign law |
DOI | 10.1007/s10409-018-0758-z |
URL | 查看原文 |
Indexed By | SCI ; EI ; CSCD |
Language | 英语 |
WOS ID | WOS:000446821000002 |
WOS Keyword | INDUCED VIBRATIONS ; SUPPRESSION ; TRANSITION ; DYNAMICS ; WAKE |
WOS Research Area | Engineering, Mechanical ; Mechanics |
WOS Subject | Engineering ; Mechanics |
Funding Organization | National Key Scientific Instrument and Equipment Development Program of China [2011YQ120048] |
CSCD ID | CSCD:6359400 |
Classification | 二类 |
Ranking | 1 |
Citation statistics |
Cited Times:3[CSCD]
[CSCD Record]
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Document Type | 期刊论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/77939 |
Collection | 流固耦合系统力学重点实验室 |
Affiliation | 1.[Lin, L. M. 2.Zhong, X. F. 3.Wu, Y. X.] Chinese Acad Sci, Inst Mech, Key Lab Mech Fluid Solid Coupling Syst, Beijing 100190, Peoples R China 4.[Wu, Y. X.] Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China |
Recommended Citation GB/T 7714 | Lin LM,Zhong XF,Wu YX. Effect of perforation on flow past a conic cylinder at Re=100: wavy vortex and sign laws[J]. ACTA MECHANICA SINICA,2018,34,5,:812-829. |
APA | Lin LM,Zhong XF,&Wu YX.(2018).Effect of perforation on flow past a conic cylinder at Re=100: wavy vortex and sign laws.ACTA MECHANICA SINICA,34(5),812-829. |
MLA | Lin LM,et al."Effect of perforation on flow past a conic cylinder at Re=100: wavy vortex and sign laws".ACTA MECHANICA SINICA 34.5(2018):812-829. |
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