---
_id: '12105'
abstract:
- lang: eng
text: Data-driven dimensionality reduction methods such as proper orthogonal decomposition
and dynamic mode decomposition have proven to be useful for exploring complex
phenomena within fluid dynamics and beyond. A well-known challenge for these techniques
is posed by the continuous symmetries, e.g. translations and rotations, of the
system under consideration, as drifts in the data dominate the modal expansions
without providing an insight into the dynamics of the problem. In the present
study, we address this issue for fluid flows in rectangular channels by formulating
a continuous symmetry reduction method that eliminates the translations in the
streamwise and spanwise directions simultaneously. We demonstrate our method by
computing the symmetry-reduced dynamic mode decomposition (SRDMD) of sliding windows
of data obtained from the transitional plane-Couette and turbulent plane-Poiseuille
flow simulations. In the former setting, SRDMD captures the dynamics in the vicinity
of the invariant solutions with translation symmetries, i.e. travelling waves
and relative periodic orbits, whereas in the latter, our calculations reveal episodes
of turbulent time evolution that can be approximated by a low-dimensional linear
expansion.
acknowledgement: "E.M. acknowledges funding from the ISTplus fellowship programme.
G.Y. and B.H. acknowledge\r\na grant from the Simons Foundation (662960, BH)."
article_number: A10
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Elena
full_name: Marensi, Elena
id: 0BE7553A-1004-11EA-B805-18983DDC885E
last_name: Marensi
- first_name: Gökhan
full_name: Yalniz, Gökhan
id: 66E74FA2-D8BF-11E9-8249-8DE2E5697425
last_name: Yalniz
orcid: 0000-0002-8490-9312
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
- first_name: Nazmi B
full_name: Budanur, Nazmi B
id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
last_name: Budanur
orcid: 0000-0003-0423-5010
citation:
ama: Marensi E, Yalniz G, Hof B, Budanur NB. Symmetry-reduced dynamic mode decomposition
of near-wall turbulence. Journal of Fluid Mechanics. 2023;954. doi:10.1017/jfm.2022.1001
apa: Marensi, E., Yalniz, G., Hof, B., & Budanur, N. B. (2023). Symmetry-reduced
dynamic mode decomposition of near-wall turbulence. Journal of Fluid Mechanics.
Cambridge University Press. https://doi.org/10.1017/jfm.2022.1001
chicago: Marensi, Elena, Gökhan Yalniz, Björn Hof, and Nazmi B Budanur. “Symmetry-Reduced
Dynamic Mode Decomposition of near-Wall Turbulence.” Journal of Fluid Mechanics.
Cambridge University Press, 2023. https://doi.org/10.1017/jfm.2022.1001.
ieee: E. Marensi, G. Yalniz, B. Hof, and N. B. Budanur, “Symmetry-reduced dynamic
mode decomposition of near-wall turbulence,” Journal of Fluid Mechanics,
vol. 954. Cambridge University Press, 2023.
ista: Marensi E, Yalniz G, Hof B, Budanur NB. 2023. Symmetry-reduced dynamic mode
decomposition of near-wall turbulence. Journal of Fluid Mechanics. 954, A10.
mla: Marensi, Elena, et al. “Symmetry-Reduced Dynamic Mode Decomposition of near-Wall
Turbulence.” Journal of Fluid Mechanics, vol. 954, A10, Cambridge University
Press, 2023, doi:10.1017/jfm.2022.1001.
short: E. Marensi, G. Yalniz, B. Hof, N.B. Budanur, Journal of Fluid Mechanics 954
(2023).
date_created: 2023-01-08T23:00:53Z
date_published: 2023-01-10T00:00:00Z
date_updated: 2023-08-01T12:53:23Z
day: '10'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1017/jfm.2022.1001
external_id:
arxiv:
- '2101.07516'
isi:
- '000903336600001'
file:
- access_level: open_access
checksum: 9224f987caefe5dd85a70814d3cce65c
content_type: application/pdf
creator: dernst
date_created: 2023-02-02T12:34:54Z
date_updated: 2023-02-02T12:34:54Z
file_id: '12489'
file_name: 2023_JourFluidMechanics_Marensi.pdf
file_size: 1931647
relation: main_file
success: 1
file_date_updated: 2023-02-02T12:34:54Z
has_accepted_license: '1'
intvolume: ' 954'
isi: 1
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
project:
- _id: 238598C6-32DE-11EA-91FC-C7463DDC885E
grant_number: '662960'
name: 'Revisiting the Turbulence Problem Using Statistical Mechanics: Experimental
Studies on Transitional and Turbulent Flows'
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Symmetry-reduced dynamic mode decomposition of near-wall turbulence
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 954
year: '2023'
...
---
_id: '14466'
abstract:
- lang: eng
text: The first long-lived turbulent structures observable in planar shear flows
take the form of localized stripes, inclined with respect to the mean flow direction.
The dynamics of these stripes is central to transition, and recent studies proposed
an analogy to directed percolation where the stripes’ proliferation is ultimately
responsible for the turbulence becoming sustained. In the present study we focus
on the internal stripe dynamics as well as on the eventual stripe expansion, and
we compare the underlying mechanisms in pressure- and shear-driven planar flows,
respectively, plane-Poiseuille and plane-Couette flow. Despite the similarities
of the overall laminar–turbulence patterns, the stripe proliferation processes
in the two cases are fundamentally different. Starting from the growth and sustenance
of individual stripes, we find that in plane-Couette flow new streaks are created
stochastically throughout the stripe whereas in plane-Poiseuille flow streak creation
is deterministic and occurs locally at the downstream tip. Because of the up/downstream
symmetry, Couette stripes, in contrast to Poiseuille stripes, have two weak and
two strong laminar turbulent interfaces. These differences in symmetry as well
as in internal growth give rise to two fundamentally different stripe splitting
mechanisms. In plane-Poiseuille flow splitting is connected to the elongational
growth of the original stripe, and it results from a break-off/shedding of the
stripe's tail. In plane-Couette flow splitting follows from a broadening of the
original stripe and a division along the stripe into two slimmer stripes.
acknowledgement: E.M. acknowledges funding from the ISTplus fellowship programme.
G.Y. and B.H. acknowledge a grant from the Simons Foundation (662960, BH).
article_number: A21
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Elena
full_name: Marensi, Elena
id: 0BE7553A-1004-11EA-B805-18983DDC885E
last_name: Marensi
orcid: 0000-0001-7173-4923
- first_name: Gökhan
full_name: Yalniz, Gökhan
id: 66E74FA2-D8BF-11E9-8249-8DE2E5697425
last_name: Yalniz
orcid: 0000-0002-8490-9312
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Marensi E, Yalniz G, Hof B. Dynamics and proliferation of turbulent stripes
in plane-Poiseuille and plane-Couette flows. Journal of Fluid Mechanics.
2023;974. doi:10.1017/jfm.2023.780
apa: Marensi, E., Yalniz, G., & Hof, B. (2023). Dynamics and proliferation of
turbulent stripes in plane-Poiseuille and plane-Couette flows. Journal of Fluid
Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2023.780
chicago: Marensi, Elena, Gökhan Yalniz, and Björn Hof. “Dynamics and Proliferation
of Turbulent Stripes in Plane-Poiseuille and Plane-Couette Flows.” Journal
of Fluid Mechanics. Cambridge University Press, 2023. https://doi.org/10.1017/jfm.2023.780.
ieee: E. Marensi, G. Yalniz, and B. Hof, “Dynamics and proliferation of turbulent
stripes in plane-Poiseuille and plane-Couette flows,” Journal of Fluid Mechanics,
vol. 974. Cambridge University Press, 2023.
ista: Marensi E, Yalniz G, Hof B. 2023. Dynamics and proliferation of turbulent
stripes in plane-Poiseuille and plane-Couette flows. Journal of Fluid Mechanics.
974, A21.
mla: Marensi, Elena, et al. “Dynamics and Proliferation of Turbulent Stripes in
Plane-Poiseuille and Plane-Couette Flows.” Journal of Fluid Mechanics,
vol. 974, A21, Cambridge University Press, 2023, doi:10.1017/jfm.2023.780.
short: E. Marensi, G. Yalniz, B. Hof, Journal of Fluid Mechanics 974 (2023).
date_created: 2023-10-30T09:32:28Z
date_published: 2023-11-10T00:00:00Z
date_updated: 2024-02-15T09:06:23Z
day: '10'
ddc:
- '530'
department:
- _id: GradSch
- _id: BjHo
doi: 10.1017/jfm.2023.780
external_id:
arxiv:
- '2212.12406'
isi:
- '001088363700001'
file:
- access_level: open_access
checksum: 17c64c1fb0d5f73252364bf98b0b9e1a
content_type: application/pdf
creator: dernst
date_created: 2024-02-15T09:05:21Z
date_updated: 2024-02-15T09:05:21Z
file_id: '14996'
file_name: 2023_JourFluidMechanics_Marensi.pdf
file_size: 2804641
relation: main_file
success: 1
file_date_updated: 2024-02-15T09:05:21Z
has_accepted_license: '1'
intvolume: ' 974'
isi: 1
keyword:
- turbulence
- transition to turbulence
- patterns
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
project:
- _id: 238598C6-32DE-11EA-91FC-C7463DDC885E
grant_number: '662960'
name: 'Revisiting the Turbulence Problem Using Statistical Mechanics: Experimental
Studies on Transitional and Turbulent Flows'
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
status: public
title: Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette
flows
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 974
year: '2023'
...
---
_id: '10925'
abstract:
- lang: eng
text: Direct numerical simulations (DNS) of turbulent channel flows up to Reτ≈1000 are
conducted to investigate the three-dimensional (consisting of streamwise wavenumber,
spanwise wavenumber and frequency) spectrum of wall pressure fluctuations. To
develop a predictive model of the wavenumber–frequency spectrum from the wavenumber
spectrum, the time decorrelation mechanisms of wall pressure fluctuations are
investigated. It is discovered that the energy-containing part of the wavenumber–frequency
spectrum of wall pressure fluctuations can be well predicted using a similar random
sweeping model for streamwise velocity fluctuations. To refine the investigation,
we further decompose the spectrum of the total wall pressure fluctuations into
the autospectra of rapid and slow pressure fluctuations, and the cross-spectrum
between them. We focus on evaluating the assumption applied in many predictive
models, that is, the magnitude of the cross-spectrum is negligibly small. The
present DNS shows that neglecting the cross-spectrum causes a maximum error up
to 4.7 dB in the subconvective region for all Reynolds numbers under test. Our
analyses indicate that the approximation of neglecting the cross-spectrum needs
to be applied carefully in the investigations of acoustics at low Mach numbers,
in which the subconvective components of wall pressure fluctuations make important
contributions to the radiated acoustic power.
acknowledgement: This research is supported by the NSFC Basic Science Center Program
for ‘Multiscale Problems in Nonlinear Mechanics’ (no. 11988102), National Key Project
(GJXM92579) and the Strategic Priority Research Program (XDB22040104).
article_number: A39
article_processing_charge: No
article_type: original
author:
- first_name: Bowen
full_name: Yang, Bowen
id: 71b6ff4b-15b2-11ec-abd3-aef6b028cf7e
last_name: Yang
orcid: 0000-0002-4843-6853
- first_name: Zixuan
full_name: Yang, Zixuan
last_name: Yang
citation:
ama: Yang B, Yang Z. On the wavenumber-frequency spectrum of the wall pressure fluctuations
in turbulent channel flow. Journal of Fluid Mechanics. 2022;937. doi:10.1017/jfm.2022.137
apa: Yang, B., & Yang, Z. (2022). On the wavenumber-frequency spectrum of the
wall pressure fluctuations in turbulent channel flow. Journal of Fluid Mechanics.
Cambridge University Press. https://doi.org/10.1017/jfm.2022.137
chicago: Yang, Bowen, and Zixuan Yang. “On the Wavenumber-Frequency Spectrum of
the Wall Pressure Fluctuations in Turbulent Channel Flow.” Journal of Fluid
Mechanics. Cambridge University Press, 2022. https://doi.org/10.1017/jfm.2022.137.
ieee: B. Yang and Z. Yang, “On the wavenumber-frequency spectrum of the wall pressure
fluctuations in turbulent channel flow,” Journal of Fluid Mechanics, vol.
937. Cambridge University Press, 2022.
ista: Yang B, Yang Z. 2022. On the wavenumber-frequency spectrum of the wall pressure
fluctuations in turbulent channel flow. Journal of Fluid Mechanics. 937, A39.
mla: Yang, Bowen, and Zixuan Yang. “On the Wavenumber-Frequency Spectrum of the
Wall Pressure Fluctuations in Turbulent Channel Flow.” Journal of Fluid Mechanics,
vol. 937, A39, Cambridge University Press, 2022, doi:10.1017/jfm.2022.137.
short: B. Yang, Z. Yang, Journal of Fluid Mechanics 937 (2022).
date_created: 2022-03-27T22:01:45Z
date_published: 2022-04-25T00:00:00Z
date_updated: 2023-08-03T06:20:26Z
day: '25'
department:
- _id: GradSch
doi: 10.1017/jfm.2022.137
external_id:
arxiv:
- '2201.04702'
isi:
- '000763547000001'
intvolume: ' 937'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1017/jfm.2022.137
month: '04'
oa: 1
oa_version: Published Version
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent
channel flow
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 937
year: '2022'
...
---
_id: '12137'
abstract:
- lang: eng
text: We investigate the local self-sustained process underlying spiral turbulence
in counter-rotating Taylor–Couette flow using a periodic annular domain, shaped
as a parallelogram, two of whose sides are aligned with the cylindrical helix
described by the spiral pattern. The primary focus of the study is placed on the
emergence of drifting–rotating waves (DRW) that capture, in a relatively small
domain, the main features of coherent structures typically observed in developed
turbulence. The transitional dynamics of the subcritical region, far below the
first instability of the laminar circular Couette flow, is determined by the upper
and lower branches of DRW solutions originated at saddle-node bifurcations. The
mechanism whereby these solutions self-sustain, and the chaotic dynamics they
induce, are conspicuously reminiscent of other subcritical shear flows. Remarkably,
the flow properties of DRW persist even as the Reynolds number is increased beyond
the linear stability threshold of the base flow. Simulations in a narrow parallelogram
domain stretched in the azimuthal direction to revolve around the apparatus a
full turn confirm that self-sustained vortices eventually concentrate into a localised
pattern. The resulting statistical steady state satisfactorily reproduces qualitatively,
and to a certain degree also quantitatively, the topology and properties of spiral
turbulence as calculated in a large periodic domain of sufficient aspect ratio
that is representative of the real system.
acknowledgement: "K.D.’s research was supported by an Australian Research Council
Discovery Early Career\r\nResearcher Award (DE170100171). B.W., R.A., F.M. and A.M.
research was supported by the Spanish Ministerio de Economía y Competitivdad (grant
numbers FIS2016-77849-R and FIS2017-85794-P) and Ministerio de Ciencia e Innovación
(grant number PID2020-114043GB-I00) and the Generalitat de Catalunya (grant 2017-SGR-785).
B.W.’s research was also supported by the Chinese Scholarship Council (grant CSC
no. 201806440152)."
article_number: A21
article_processing_charge: No
article_type: original
author:
- first_name: B.
full_name: Wang, B.
last_name: Wang
- first_name: Roger
full_name: Ayats López, Roger
id: ab77522d-073b-11ed-8aff-e71b39258362
last_name: Ayats López
orcid: 0000-0001-6572-0621
- first_name: K.
full_name: Deguchi, K.
last_name: Deguchi
- first_name: F.
full_name: Mellibovsky, F.
last_name: Mellibovsky
- first_name: A.
full_name: Meseguer, A.
last_name: Meseguer
citation:
ama: Wang B, Ayats López R, Deguchi K, Mellibovsky F, Meseguer A. Self-sustainment
of coherent structures in counter-rotating Taylor–Couette flow. Journal of
Fluid Mechanics. 2022;951. doi:10.1017/jfm.2022.828
apa: Wang, B., Ayats López, R., Deguchi, K., Mellibovsky, F., & Meseguer, A.
(2022). Self-sustainment of coherent structures in counter-rotating Taylor–Couette
flow. Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2022.828
chicago: Wang, B., Roger Ayats López, K. Deguchi, F. Mellibovsky, and A. Meseguer.
“Self-Sustainment of Coherent Structures in Counter-Rotating Taylor–Couette Flow.”
Journal of Fluid Mechanics. Cambridge University Press, 2022. https://doi.org/10.1017/jfm.2022.828.
ieee: B. Wang, R. Ayats López, K. Deguchi, F. Mellibovsky, and A. Meseguer, “Self-sustainment
of coherent structures in counter-rotating Taylor–Couette flow,” Journal of
Fluid Mechanics, vol. 951. Cambridge University Press, 2022.
ista: Wang B, Ayats López R, Deguchi K, Mellibovsky F, Meseguer A. 2022. Self-sustainment
of coherent structures in counter-rotating Taylor–Couette flow. Journal of Fluid
Mechanics. 951, A21.
mla: Wang, B., et al. “Self-Sustainment of Coherent Structures in Counter-Rotating
Taylor–Couette Flow.” Journal of Fluid Mechanics, vol. 951, A21, Cambridge
University Press, 2022, doi:10.1017/jfm.2022.828.
short: B. Wang, R. Ayats López, K. Deguchi, F. Mellibovsky, A. Meseguer, Journal
of Fluid Mechanics 951 (2022).
date_created: 2023-01-12T12:04:17Z
date_published: 2022-11-07T00:00:00Z
date_updated: 2023-08-04T08:54:16Z
day: '07'
department:
- _id: BjHo
doi: 10.1017/jfm.2022.828
external_id:
arxiv:
- '2207.12990'
isi:
- '000879446900001'
intvolume: ' 951'
isi: 1
keyword:
- Mechanical Engineering
- Mechanics of Materials
- Condensed Matter Physics
- Applied Mathematics
language:
- iso: eng
main_file_link:
- open_access: '1'
url: ' https://doi.org/10.48550/arXiv.2207.12990'
month: '11'
oa: 1
oa_version: Preprint
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Self-sustainment of coherent structures in counter-rotating Taylor–Couette
flow
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 951
year: '2022'
...
---
_id: '9207'
abstract:
- lang: eng
text: "In this paper we experimentally study the transitional range of Reynolds
numbers in\r\nplane Couette–Poiseuille flow, focusing our attention on the localized
turbulent structures\r\ntriggered by a strong impulsive jet and the large-scale
flow generated around these\r\nstructures. We present a detailed investigation
of the large-scale flow and show how\r\nits amplitude depends on Reynolds number
and amplitude perturbation. In addition,\r\nwe characterize the initial dynamics
of the localized turbulent spot, which includes the\r\ncoupling between the small
and large scales, as well as the dependence of the advection\r\nspeed on the large-scale
flow generated around the spot. Finally, we provide the first\r\nexperimental
measurements of the large-scale flow around an oblique turbulent band."
acknowledgement: "We thank Y. Duguet, S. Gomé, G. Lemoult, T. Liu, B. Semin and L.S.
Tuckerman for\r\nfruitful discussions. \r\nThis work was supported by a grant, TRANSFLOW,
provided by the Agence Nationale de\r\nla Recherche (ANR). A.M.P. was partially
supported by the French Embassy in Russia (I.I. Mechnikov scholarship) and by the
Russian Science Foundation (project no. 18-79-00189). L.K. was partially supported
by the European Union’s Horizon 2020 research and innovation programme under the
Marie Skłodowska-Curie grant agreement no. 754411."
article_number: A24
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Lukasz
full_name: Klotz, Lukasz
id: 2C9AF1C2-F248-11E8-B48F-1D18A9856A87
last_name: Klotz
orcid: 0000-0003-1740-7635
- first_name: A. M.
full_name: Pavlenko, A. M.
last_name: Pavlenko
- first_name: J. E.
full_name: Wesfreid, J. E.
last_name: Wesfreid
citation:
ama: 'Klotz L, Pavlenko AM, Wesfreid JE. Experimental measurements in plane Couette-Poiseuille
flow: Dynamics of the large- and small-scale flow. Journal of Fluid Mechanics.
2021;912. doi:10.1017/jfm.2020.1089'
apa: 'Klotz, L., Pavlenko, A. M., & Wesfreid, J. E. (2021). Experimental measurements
in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow.
Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2020.1089'
chicago: 'Klotz, Lukasz, A. M. Pavlenko, and J. E. Wesfreid. “Experimental Measurements
in Plane Couette-Poiseuille Flow: Dynamics of the Large- and Small-Scale Flow.”
Journal of Fluid Mechanics. Cambridge University Press, 2021. https://doi.org/10.1017/jfm.2020.1089.'
ieee: 'L. Klotz, A. M. Pavlenko, and J. E. Wesfreid, “Experimental measurements
in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow,”
Journal of Fluid Mechanics, vol. 912. Cambridge University Press, 2021.'
ista: 'Klotz L, Pavlenko AM, Wesfreid JE. 2021. Experimental measurements in plane
Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. Journal
of Fluid Mechanics. 912, A24.'
mla: 'Klotz, Lukasz, et al. “Experimental Measurements in Plane Couette-Poiseuille
Flow: Dynamics of the Large- and Small-Scale Flow.” Journal of Fluid Mechanics,
vol. 912, A24, Cambridge University Press, 2021, doi:10.1017/jfm.2020.1089.'
short: L. Klotz, A.M. Pavlenko, J.E. Wesfreid, Journal of Fluid Mechanics 912 (2021).
date_created: 2021-02-28T23:01:25Z
date_published: 2021-02-15T00:00:00Z
date_updated: 2023-08-07T13:55:40Z
day: '15'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1017/jfm.2020.1089
ec_funded: 1
external_id:
isi:
- '000618034400001'
file:
- access_level: open_access
checksum: b8020d6338667673e34fde0608913dd2
content_type: application/pdf
creator: dernst
date_created: 2021-03-03T09:49:34Z
date_updated: 2021-03-03T09:49:34Z
file_id: '9220'
file_name: 2021_JourFluidMechanics_Klotz.pdf
file_size: 4124471
relation: main_file
success: 1
file_date_updated: 2021-03-03T09:49:34Z
has_accepted_license: '1'
intvolume: ' 912'
isi: 1
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '754411'
name: ISTplus - Postdoctoral Fellowships
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the
large- and small-scale flow'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 912
year: '2021'
...
---
_id: '9297'
abstract:
- lang: eng
text: 'We report the results of an experimental investigation into the decay of
turbulence in plane Couette–Poiseuille flow using ‘quench’ experiments where the
flow laminarises after a sudden reduction in Reynolds number Re. Specifically,
we study the velocity field in the streamwise–spanwise plane. We show that the
spanwise velocity containing rolls decays faster than the streamwise velocity,
which displays elongated regions of higher or lower velocity called streaks. At
final Reynolds numbers above 425, the decay of streaks displays two stages: first
a slow decay when rolls are present and secondly a more rapid decay of streaks
alone. The difference in behaviour results from the regeneration of streaks by
rolls, called the lift-up effect. We define the turbulent fraction as the portion
of the flow containing turbulence and this is estimated by thresholding the spanwise
velocity component. It decreases linearly with time in the whole range of final
Re. The corresponding decay slope increases linearly with final Re. The extrapolated
value at which this decay slope vanishes is Reaz≈656±10, close to Reg≈670 at which
turbulence is self-sustained. The decay of the energy computed from the spanwise
velocity component is found to be exponential. The corresponding decay rate increases
linearly with Re, with an extrapolated vanishing value at ReAz≈688±10. This value
is also close to the value at which the turbulence is self-sustained, showing
that valuable information on the transition can be obtained over a wide range
of Re.'
acknowledgement: "We gratefully acknowledge Joran Rolland, Yohann Duguet, Romain Monchaux,
S´ebastien Gom´e, Laurette Tuckerman, Dwight Barkley, Olivier Dauchot and Sabine
Bottin for fruitful discussions. We thank Xavier Benoit-Gonin, Amaury Fourgeaud,
Thierry Darnige, Olivier Brouard and Justine Laurent for technical help. This work
has benefited from the ANR TransFlow, and by starting grants obtained by B.S. from
CNRS (INSIS) and ESPCI. T.M. was\r\nsupported by a Joliot visiting professorship
grant from ESPCI."
article_number: A65
article_processing_charge: No
article_type: original
author:
- first_name: T.
full_name: Liu, T.
last_name: Liu
- first_name: B.
full_name: Semin, B.
last_name: Semin
- first_name: Lukasz
full_name: Klotz, Lukasz
id: 2C9AF1C2-F248-11E8-B48F-1D18A9856A87
last_name: Klotz
orcid: 0000-0003-1740-7635
- first_name: R.
full_name: Godoy-Diana, R.
last_name: Godoy-Diana
- first_name: J. E.
full_name: Wesfreid, J. E.
last_name: Wesfreid
- first_name: T.
full_name: Mullin, T.
last_name: Mullin
citation:
ama: Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. Decay of streaks
and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics.
2021;915. doi:10.1017/jfm.2021.89
apa: Liu, T., Semin, B., Klotz, L., Godoy-Diana, R., Wesfreid, J. E., & Mullin,
T. (2021). Decay of streaks and rolls in plane Couette-Poiseuille flow. Journal
of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2021.89
chicago: Liu, T., B. Semin, Lukasz Klotz, R. Godoy-Diana, J. E. Wesfreid, and T.
Mullin. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.” Journal
of Fluid Mechanics. Cambridge University Press, 2021. https://doi.org/10.1017/jfm.2021.89.
ieee: T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J. E. Wesfreid, and T. Mullin,
“Decay of streaks and rolls in plane Couette-Poiseuille flow,” Journal of Fluid
Mechanics, vol. 915. Cambridge University Press, 2021.
ista: Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. 2021. Decay
of streaks and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics.
915, A65.
mla: Liu, T., et al. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.”
Journal of Fluid Mechanics, vol. 915, A65, Cambridge University Press,
2021, doi:10.1017/jfm.2021.89.
short: T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J.E. Wesfreid, T. Mullin, Journal
of Fluid Mechanics 915 (2021).
date_created: 2021-03-28T22:01:42Z
date_published: 2021-03-17T00:00:00Z
date_updated: 2023-08-07T14:30:11Z
day: '17'
department:
- _id: BjHo
doi: 10.1017/jfm.2021.89
external_id:
arxiv:
- '2008.08851'
isi:
- '000629677500001'
intvolume: ' 915'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2008.08851
month: '03'
oa: 1
oa_version: Preprint
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Decay of streaks and rolls in plane Couette-Poiseuille flow
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 915
year: '2021'
...
---
_id: '7397'
abstract:
- lang: eng
text: Polymer additives can substantially reduce the drag of turbulent flows and
the upperlimit, the so called “maximum drag reduction” (MDR) asymptote is universal,
i.e. inde-pendent of the type of polymer and solvent used. Until recently, the
consensus was that,in this limit, flows are in a marginal state where only a minimal
level of turbulence activ-ity persists. Observations in direct numerical simulations
using minimal sized channelsappeared to support this view and reported long “hibernation” periods where turbu-lence
is marginalized. In simulations of pipe flow we find that, indeed, with increasingWeissenberg
number (Wi), turbulence expresses long periods of hibernation if the domainsize
is small. However, with increasing pipe length, the temporal hibernation continuouslyalters
to spatio-temporal intermittency and here the flow consists of turbulent puffs
sur-rounded by laminar flow. Moreover, upon an increase in Wi, the flow fully
relaminarises,in agreement with recent experiments. At even larger Wi, a different
instability is en-countered causing a drag increase towards MDR. Our findings
hence link earlier minimalflow unit simulations with recent experiments and confirm
that the addition of polymersinitially suppresses Newtonian turbulence and leads
to a reverse transition. The MDRstate on the other hand results from a separate
instability and the underlying dynamicscorresponds to the recently proposed state
of elasto-inertial-turbulence (EIT).
article_processing_charge: No
article_type: original
author:
- first_name: Jose M
full_name: Lopez Alonso, Jose M
id: 40770848-F248-11E8-B48F-1D18A9856A87
last_name: Lopez Alonso
orcid: 0000-0002-0384-2022
- first_name: George H
full_name: Choueiri, George H
id: 448BD5BC-F248-11E8-B48F-1D18A9856A87
last_name: Choueiri
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Lopez Alonso JM, Choueiri GH, Hof B. Dynamics of viscoelastic pipe flow at
low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid
Mechanics. 2019;874:699-719. doi:10.1017/jfm.2019.486
apa: Lopez Alonso, J. M., Choueiri, G. H., & Hof, B. (2019). Dynamics of viscoelastic
pipe flow at low Reynolds numbers in the maximum drag reduction limit. Journal
of Fluid Mechanics. CUP. https://doi.org/10.1017/jfm.2019.486
chicago: Lopez Alonso, Jose M, George H Choueiri, and Björn Hof. “Dynamics of Viscoelastic
Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” Journal
of Fluid Mechanics. CUP, 2019. https://doi.org/10.1017/jfm.2019.486.
ieee: J. M. Lopez Alonso, G. H. Choueiri, and B. Hof, “Dynamics of viscoelastic
pipe flow at low Reynolds numbers in the maximum drag reduction limit,” Journal
of Fluid Mechanics, vol. 874. CUP, pp. 699–719, 2019.
ista: Lopez Alonso JM, Choueiri GH, Hof B. 2019. Dynamics of viscoelastic pipe flow
at low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid
Mechanics. 874, 699–719.
mla: Lopez Alonso, Jose M., et al. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds
Numbers in the Maximum Drag Reduction Limit.” Journal of Fluid Mechanics,
vol. 874, CUP, 2019, pp. 699–719, doi:10.1017/jfm.2019.486.
short: J.M. Lopez Alonso, G.H. Choueiri, B. Hof, Journal of Fluid Mechanics 874
(2019) 699–719.
date_created: 2020-01-29T16:05:19Z
date_published: 2019-09-10T00:00:00Z
date_updated: 2023-09-06T15:36:36Z
day: '10'
department:
- _id: BjHo
doi: 10.1017/jfm.2019.486
external_id:
arxiv:
- '1808.04080'
isi:
- '000475349900001'
intvolume: ' 874'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1808.04080
month: '09'
oa: 1
oa_version: Preprint
page: 699-719
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: CUP
quality_controlled: '1'
scopus_import: '1'
status: public
title: Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag
reduction limit
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 874
year: '2019'
...
---
_id: '5996'
abstract:
- lang: eng
text: 'In pipes, turbulence sets in despite the linear stability of the laminar
Hagen–Poiseuille flow. The Reynolds number ( ) for which turbulence first appears
in a given experiment – the ‘natural transition point’ – depends on imperfections
of the set-up, or, more precisely, on the magnitude of finite amplitude perturbations.
At onset, turbulence typically only occupies a certain fraction of the flow, and
this fraction equally is found to differ from experiment to experiment. Despite
these findings, Reynolds proposed that after sufficiently long times, flows may
settle to steady conditions: below a critical velocity, flows should (regardless
of initial conditions) always return to laminar, while above this velocity, eddying
motion should persist. As will be shown, even in pipes several thousand diameters
long, the spatio-temporal intermittent flow patterns observed at the end of the
pipe strongly depend on the initial conditions, and there is no indication that
different flow patterns would eventually settle to a (statistical) steady state.
Exploiting the fact that turbulent puffs do not age (i.e. they are memoryless),
we continuously recreate the puff sequence exiting the pipe at the pipe entrance,
and in doing so introduce periodic boundary conditions for the puff pattern. This
procedure allows us to study the evolution of the flow patterns for arbitrary
long times, and we find that after times in excess of advective time units, indeed
a statistical steady state is reached. Although the resulting flows remain spatio-temporally
intermittent, puff splitting and decay rates eventually reach a balance, so that
the turbulent fraction fluctuates around a well-defined level which only depends
on . In accordance with Reynolds’ proposition, we find that at lower (here 2020),
flows eventually always resume to laminar, while for higher ( ), turbulence persists.
The critical point for pipe flow hence falls in the interval of $2020 , which
is in very good agreement with the recently proposed value of . The latter estimate
was based on single-puff statistics and entirely neglected puff interactions.
Unlike in typical contact processes where such interactions strongly affect the
percolation threshold, in pipe flow, the critical point is only marginally influenced.
Interactions, on the other hand, are responsible for the approach to the statistical
steady state. As shown, they strongly affect the resulting flow patterns, where
they cause ‘puff clustering’, and these regions of large puff densities are observed
to travel across the puff pattern in a wave-like fashion.'
acknowledgement: ' We also thank Philipp Maier and the IST Austria workshop for theirdedicated
technical support'
article_processing_charge: No
article_type: original
author:
- first_name: Mukund
full_name: Vasudevan, Mukund
id: 3C5A959A-F248-11E8-B48F-1D18A9856A87
last_name: Vasudevan
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Vasudevan M, Hof B. The critical point of the transition to turbulence in pipe
flow. Journal of Fluid Mechanics. 2018;839:76-94. doi:10.1017/jfm.2017.923
apa: Vasudevan, M., & Hof, B. (2018). The critical point of the transition to
turbulence in pipe flow. Journal of Fluid Mechanics. Cambridge University
Press. https://doi.org/10.1017/jfm.2017.923
chicago: Vasudevan, Mukund, and Björn Hof. “The Critical Point of the Transition
to Turbulence in Pipe Flow.” Journal of Fluid Mechanics. Cambridge University
Press, 2018. https://doi.org/10.1017/jfm.2017.923.
ieee: M. Vasudevan and B. Hof, “The critical point of the transition to turbulence
in pipe flow,” Journal of Fluid Mechanics, vol. 839. Cambridge University
Press, pp. 76–94, 2018.
ista: Vasudevan M, Hof B. 2018. The critical point of the transition to turbulence
in pipe flow. Journal of Fluid Mechanics. 839, 76–94.
mla: Vasudevan, Mukund, and Björn Hof. “The Critical Point of the Transition to
Turbulence in Pipe Flow.” Journal of Fluid Mechanics, vol. 839, Cambridge
University Press, 2018, pp. 76–94, doi:10.1017/jfm.2017.923.
short: M. Vasudevan, B. Hof, Journal of Fluid Mechanics 839 (2018) 76–94.
date_created: 2019-02-14T12:50:50Z
date_published: 2018-03-25T00:00:00Z
date_updated: 2023-09-19T14:37:49Z
day: '25'
department:
- _id: BjHo
doi: 10.1017/jfm.2017.923
ec_funded: 1
external_id:
arxiv:
- '1709.06372'
isi:
- '000437858300003'
intvolume: ' 839'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1709.06372
month: '03'
oa: 1
oa_version: Preprint
page: 76-94
project:
- _id: 25152F3A-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '306589'
name: Decoding the complexity of turbulence at its origin
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: The critical point of the transition to turbulence in pipe flow
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 839
year: '2018'
...