Convection and correlation of coherent structure in turbulent boundary layer using tomographic particle image velocimetry | |
Wang W(王维); Guan XL(管新蕾); Jiang N(姜楠)![]() | |
Source Publication | Chinese Physics B
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2014-10 | |
Volume | 23Issue:10Pages:104703 |
ISSN | 1674-1056 |
Abstract | The present experimental work focuses on a new model for space-time correlation and the scale-dependencies of convection velocity and sweep velocity in turbulent boundary layer over a flat wall. A turbulent boundary layer flow at Re-theta = 2460 is measured by tomographic particle image velocimetry (tomographic PIV). It is demonstrated that arch, cane, and hairpin vortices are dominant in the logarithmic layer. Hairpins and hairpin packets are responsible for the elongated low-momentum zones observed in the instantaneous flow field. The conditionally-averaged coherent structures systemically illustrate the key roles of hairpin vortice in the turbulence dynamic events, such as ejection and sweep events and energy transport. The space-time correlations of instantaneous streamwise fluctuation velocity are calculated and confirm the new elliptic model for the space-time correlation instead of Taylor hypothesis. The convection velocities derived from the space-time correlation and conditionally-averaged method both suggest the scaling with the local mean velocity in the logarithmic layer. Convection velocity result based on Fourier decomposition (FD) shows stronger scale-dependency in the spanwise direction than in streamwise direction. Compared with FD, the proper orthogonal decomposition (POD) has a distinct distribution of convection velocity for the large-and small-scales which are separated in light of their contributions of turbulent kinetic energy. |
Keyword | Turbulent Boundary Layer Tomographic Particle Image Velocimetry Space-time Correlation Elliptic Model |
Subject Area | Physics |
URL | 查看原文 |
Indexed By | SCI ; EI ; CSCD |
Language | 英语 |
WOS ID | WOS:000344057600052 |
Funding Organization | Project supported by the National Natural Science Foundation of China (Grant Nos. 11332006 and 11272233) and the National Key Basic Research and Development Program of China (Grant No. 2012CB720101). |
Classification | 二类/Q2 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/49309 |
Collection | 非线性力学国家重点实验室 |
Corresponding Author | Jiang, N (reprint author), Tianjin Univ, Dept Mech, Tianjin 300072, Peoples R China. |
Recommended Citation GB/T 7714 | Wang W,Guan XL,Jiang N,et al. Convection and correlation of coherent structure in turbulent boundary layer using tomographic particle image velocimetry[J]. Chinese Physics B,2014,23,10,:104703. |
APA | Wang W,Guan XL,Jiang N,&Jiang, N .(2014).Convection and correlation of coherent structure in turbulent boundary layer using tomographic particle image velocimetry.Chinese Physics B,23(10),104703. |
MLA | Wang W,et al."Convection and correlation of coherent structure in turbulent boundary layer using tomographic particle image velocimetry".Chinese Physics B 23.10(2014):104703. |
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