Streamlines in stationary homogeneous isotropic turbulence
and fractal-generated turbulence
and fractal-generated turbulence
File(s)streamlines_iso_aniso_no_blue.pdf (2.45 MB)
Accepted version
Author(s)
Vassilicos, C
Type
Journal Article
Abstract
We compare streamline statistics in stationary homogeneous isotropic turbulence and in turbulence generated by a fractal square grid. We examine streamline segments characterised by the velocity difference ${\rm{\Delta }}u$ and the distance l between extremum points. We find close agreement between the stationary homogeneous isotropic turbulence and the decay region of the fractal-generated turbulence as well as the production region of the fractal flow for small segments. The statistics of larger segments are very similar for the isotropic turbulence and the decay region, but differ for the production region. Specifically, we examine the first, second and third conditional mean $\langle {[{\rm{\Delta }}u]}^{n}| l\rangle $. Noticeably, non-vanishing $\langle {[{\rm{\Delta }}u]}^{n}| l\rangle $ for $n=1,3$ are due to an asymmetry of positive and negative segments, i.e. those for which ${\rm{\Delta }}u\gt 0$ and ${\rm{\Delta }}u\lt 0$, respectively. This asymmetry is not only kinematic, but is also due to dissipative effects and therefore $\langle {[{\rm{\Delta }}u]}^{n}| l\rangle $ contains cascade information.
Date Issued
2016-02-08
Date Acceptance
2015-12-24
Citation
Fluid Dynamics Research, 2016, 48 (2)
ISSN
1873-7005
Publisher
IOP Publishing
Journal / Book Title
Fluid Dynamics Research
Volume
48
Issue
2
Copyright Statement
© 2016 IOP Publishing Ltd. J Boschung et al 2016 Fluid Dyn. Res. 48 021403
Subjects
Fluids & Plasmas
0102 Applied Mathematics
0913 Mechanical Engineering
0915 Interdisciplinary Engineering
Notes
journal_title: Fluid Dynamics Research article_type: paper article_title: Streamlines in stationary homogeneous isotropic turbulence and fractal-generated turbulence copyright_information: © 2016 The Japan Society of Fluid Mechanics and IOP Publishing Ltd date_received: 2015-07-01 date_accepted: 2015-12-24 date_epub: 2016-02-08
Publication Status
Published
Article Number
021403