Direct numerical simulation of compressible turbulence in a
counter-flow channel configuration
counter-flow channel configuration
File(s)
Accepted version
Author(s)
Hamzehloo, Arash
Lusher, David
Laizet, Sylvain
Sandham, Neil
Type
Journal Article
Abstract
Counter-flow configurations, whereby two streams of fluid are brought together from opposite
directions, are highly efficient mixers due to the high turbulence intensities that can be maintained.
In this paper, a simplified version of the problem is introduced that is amenable to direct numerical
simulation. The resulting turbulent flow problem is confined between two walls, with one non-zero
mean velocity component varying in the space direction normal to the wall, corresponding to a
simple shear flow. Compared to conventional channel flows, the mean flow is inflectional and the
maximum turbulence intensity relative to the maximum mean velocity is nearly an order of magnitude higher. The numerical requirements and turbulence properties of this configuration are first
determined. The Reynolds shear stress is required to vary linearly by the imposed forcing, with
a peak at the channel centreline. A similar behaviour is observed for the streamwise Reynolds
stress, the budget of which shows an approximately uniform distribution of dissipation, with large
contributions from production, pressure-strain and turbulent diffusion. A viscous sublayer is obtained near the walls and with increasing Reynolds number small-scale streaks in the streamwise
momentum are observed, superimposed on the large-scale structures that buffet this region. When
the peak local mean Mach number reaches 0.55, turbulent Mach numbers of 0.6 are obtained,
indicating that this flow configuration can be useful to study compressibility effects on turbulence.
directions, are highly efficient mixers due to the high turbulence intensities that can be maintained.
In this paper, a simplified version of the problem is introduced that is amenable to direct numerical
simulation. The resulting turbulent flow problem is confined between two walls, with one non-zero
mean velocity component varying in the space direction normal to the wall, corresponding to a
simple shear flow. Compared to conventional channel flows, the mean flow is inflectional and the
maximum turbulence intensity relative to the maximum mean velocity is nearly an order of magnitude higher. The numerical requirements and turbulence properties of this configuration are first
determined. The Reynolds shear stress is required to vary linearly by the imposed forcing, with
a peak at the channel centreline. A similar behaviour is observed for the streamwise Reynolds
stress, the budget of which shows an approximately uniform distribution of dissipation, with large
contributions from production, pressure-strain and turbulent diffusion. A viscous sublayer is obtained near the walls and with increasing Reynolds number small-scale streaks in the streamwise
momentum are observed, superimposed on the large-scale structures that buffet this region. When
the peak local mean Mach number reaches 0.55, turbulent Mach numbers of 0.6 are obtained,
indicating that this flow configuration can be useful to study compressibility effects on turbulence.
Date Issued
2021-09-09
Date Acceptance
2021-08-09
Citation
Physical Review Fluids, 2021, 6, pp.1-21
ISSN
2469-990X
Publisher
American Physical Society
Start Page
1
End Page
21
Journal / Book Title
Physical Review Fluids
Volume
6
Copyright Statement
©2021 American Physical Society
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.6.094603
Grant Number
EP/R023926/1
Subjects
0102 Applied Mathematics
0203 Classical Physics
0913 Mechanical Engineering
Publication Status
Published
Date Publish Online
2021-09-09