Vortex dislocations in wake-type flow induced by spanwise disturbances
文献类型：期刊论文
| 作者 | Ling GC(凌国灿) ; Zhao HL(赵红亮); Ling GC
|
| 刊名 | Physics of Fluids
 |
| 出版日期 | 2009 |
| 卷号 | 21期号:7页码:73604 |
| 通讯作者邮箱 | linggc@imech.ac.cn |
| 关键词 | Flow Simulation Numerical Analysis Shear Flow Vortices Wakes Square-Section Cylinder Circular-Cylinder Transition Turbulence Dynamics |
| ISSN号 | 1070-6631 |
| 通讯作者 | Ling GC |
| 中文摘要 | Vortex dislocations in wake-type flow induced by three types of spanwise disturbances superimposed on an upstream velocity profile are investigated by direct numerical simulations. Three distinct modes of vortex dislocations and flow transitions have been found. A local spanwise exponential decay disturbance leads to the appearance of a twisted chainlike mode of vortex dislocation. A stepped spanwise disturbance causes a streamwise periodic spotlike mode of vortex dislocation. A spanwise sinusoidal wavy disturbance with a moderate waviness causes a strong unsteadiness of wake behavior. This unsteadiness starts with a systematic periodic mode of vortex dislocation in the spanwise direction followed by the spanwise vortex shedding suppressed completely with increased time and the near wake becoming a steady shear flow. Characteristics of these modes of vortex dislocation and complex vortex linkages over the dislocation, as well as the corresponding dynamic processes related to the appearance of dislocations, are described by examining the variations of vortex lines and vorticity distribution. The nature of the vortex dislocation is demonstrated by the substantial vorticity modification of the spanwise vortex from the original spanwise direction to streamwise and vertical directions, accompanied by the appearance of noticeable vortex branching and complex vortex linking, all of which are produced at the locations with the biggest phase difference or with a frequency discontinuity between shedding cells. The effect of vortex dislocation on flow transition, either to an unsteady irregular vortex flow or suppression of the Kaacutermaacuten vortex shedding making the wake flow steady state, is analyzed. Distinct similarities are found in the mechanism and main flow phenomena between the present numerical results obtained in wake-type flows and the experimental-numerical results of cylinder wakes reported in previous studies. |
| 类目[WOS] | Mechanics ; Physics, Fluids & Plasmas |
| 研究领域[WOS] | Mechanics ; Physics |
| 关键词[WOS] | SQUARE-SECTION CYLINDER ; CIRCULAR-CYLINDER ; TRANSITION ; TURBULENCE ; DYNAMICS |
| 收录类别 | SCI |
| 资助信息 | Chinese Academy of Sciences (CAS) [KJCX2-YW-L02]; National Natural Science Foundation of China [10272104] |
| 语种 | 英语 |
| WOS记录号 | WOS:000268614900022 |
| 公开日期 | 2009-08-03 ; 2010-06-03 |
| 源URL | [http://dspace.imech.ac.cn/handle/311007/33531]  |
| 专题 | 力学研究所_非线性力学国家重点实验室 |
| 通讯作者 | Ling GC |
| 推荐引用方式 GB/T 7714 | Ling GC,Zhao HL,Ling GC. Vortex dislocations in wake-type flow induced by spanwise disturbances[J]. Physics of Fluids,2009,21(7):73604. |
| APA | 凌国灿,赵红亮,&Ling GC.(2009).Vortex dislocations in wake-type flow induced by spanwise disturbances.Physics of Fluids,21(7),73604. |
| MLA | 凌国灿,et al."Vortex dislocations in wake-type flow induced by spanwise disturbances".Physics of Fluids 21.7(2009):73604. |
入库方式： OAI收割
来源：力学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。