期刊
JOURNAL OF FLUID MECHANICS
卷 920, 期 -, 页码 -出版社
CAMBRIDGE UNIV PRESS
DOI: 10.1017/jfm.2021.478
关键词
boundary layer structure; turbulent boundary layers
资金
- Institute on the Environment (IonE)
- Australian Research Council
- University of Minnesota Graduate School
- National Science Foundation [NSF-AGS-2031312]
- National Science Foundation CAREER grant [NSF-CBET-1351303]
The statistical properties of prograde spanwise vortex cores and internal shear layers in high-Reynolds-number turbulent boundary layers are evaluated. Results show the importance of the local large-eddy turnover time in determining the strain rate confining the size of the vortex cores and shear layers. The study highlights the relevance of the turnover time and the Taylor microscale in explaining the interaction of coherent velocity structures in the boundary layer flows.
The statistical properties of prograde spanwise vortex cores and internal shear layers (ISLs) are evaluated for a series of high-Reynolds-number turbulent boundary layers. The considered flows span a wide range of both Reynolds number and surface roughness. In each case, the largest spanwise vortex cores in the outer layer of the boundary layer have size comparable to the Taylor microscale lambda(T), and the azimuthal velocity of these large vortex cores is governed by the friction velocity u(tau). The same scaling parameters describe the average thickness and velocity difference across the ISLs. The results demonstrate the importance of the local large-eddy turnover time in determining the strain rate confining the size of the vortex cores and shear layers. The relevance of the turnover time, and more generally the Taylor microscale, can be explained by a stretching mechanism involving the mutual interaction of coherent velocity structures such as uniform momentum zones with the evolving shear layers separating the structures.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据