---
_id: '12165'
abstract:
- lang: eng
text: It may come as a surprise that a phenomenon as ubiquitous and prominent as
the transition from laminar to turbulent flow has resisted combined efforts by
physicists, engineers and mathematicians, and remained unresolved for almost one
and a half centuries. In recent years, various studies have proposed analogies
to directed percolation, a well-known universality class in statistical mechanics,
which describes a non-equilibrium phase transition from a fluctuating active phase
into an absorbing state. It is this unlikely relation between the multiscale,
high-dimensional dynamics that signify the transition process in virtually all
flows of practical relevance, and the arguably most basic non-equilibrium phase
transition, that so far has mainly been the subject of model studies, which I
review in this Perspective.
article_processing_charge: No
article_type: original
author:
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Hof B. Directed percolation and the transition to turbulence. Nature Reviews
Physics. 2023;5:62-72. doi:10.1038/s42254-022-00539-y
apa: Hof, B. (2023). Directed percolation and the transition to turbulence. Nature
Reviews Physics. Springer Nature. https://doi.org/10.1038/s42254-022-00539-y
chicago: Hof, Björn. “Directed Percolation and the Transition to Turbulence.” Nature
Reviews Physics. Springer Nature, 2023. https://doi.org/10.1038/s42254-022-00539-y.
ieee: B. Hof, “Directed percolation and the transition to turbulence,” Nature
Reviews Physics, vol. 5. Springer Nature, pp. 62–72, 2023.
ista: Hof B. 2023. Directed percolation and the transition to turbulence. Nature
Reviews Physics. 5, 62–72.
mla: Hof, Björn. “Directed Percolation and the Transition to Turbulence.” Nature
Reviews Physics, vol. 5, Springer Nature, 2023, pp. 62–72, doi:10.1038/s42254-022-00539-y.
short: B. Hof, Nature Reviews Physics 5 (2023) 62–72.
date_created: 2023-01-12T12:10:18Z
date_published: 2023-01-01T00:00:00Z
date_updated: 2023-08-01T12:50:48Z
day: '01'
department:
- _id: BjHo
doi: 10.1038/s42254-022-00539-y
external_id:
isi:
- '000890148700002'
intvolume: ' 5'
isi: 1
keyword:
- General Physics and Astronomy
language:
- iso: eng
month: '01'
oa_version: None
page: 62-72
publication: Nature Reviews Physics
publication_identifier:
eissn:
- 2522-5820
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Directed percolation and the transition to turbulence
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 5
year: '2023'
...
---
_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: '12681'
abstract:
- lang: eng
text: The dissolution of minute concentration of polymers in wall-bounded flows
is well-known for its unparalleled ability to reduce turbulent friction drag.
Another phenomenon, elasto-inertial turbulence (EIT), has been far less studied
even though elastic instabilities have already been observed in dilute polymer
solutions before the discovery of polymer drag reduction. EIT is a chaotic state
driven by polymer dynamics that is observed across many orders of magnitude in
Reynolds number. It involves energy transfer from small elastic scales to large
flow scales. The investigation of the mechanisms of EIT offers the possibility
to better understand other complex phenomena such as elastic turbulence and maximum
drag reduction. In this review, we survey recent research efforts that are advancing
the understanding of the dynamics of EIT. We highlight the fundamental differences
between EIT and Newtonian/inertial turbulence from the perspective of experiments,
numerical simulations, instabilities, and coherent structures. Finally, we discuss
the possible links between EIT and elastic turbulence and polymer drag reduction,
as well as the remaining challenges in unraveling the self-sustaining mechanism
of EIT.
acknowledgement: Part of the material presented here is based upon work supported
by the National Science Foundation CBET (Chemical, Bioengineering, Environmental
and Transport Systems) award 1805636 (to Y.D.), the Binational Science Foundation
award 2016145 (to Y.D. and Victor Steinberg), a FRIA (Fund for Research Training
in Industry and Agriculture) grant of the Belgian F.R.S.-FNRS (National Fund for
Scientific Research) (to V.E.T.), the Marie Curie FP7 Career Integration grant PCIG10-GA-2011-304073
(to V.E.T.), and the Fonds spéciaux pour la recherche grant C-13/19 of the University
of Liege (to V.E.T.). Computational resources have been provided by the Consortium
des Équipements de Calcul Intensif (CECI) funded by the Belgian F.R.S.-FNRS, the
Vermont Advanced Computing Center (VACC), the Partnership for Advanced Computing
in Europe (PRACE), and the Tier-1 supercomputer of the Fédération Wallonie-Bruxelles
funded by the Walloon Region (grant agreement 117545).
article_processing_charge: No
article_type: original
author:
- first_name: Yves
full_name: Dubief, Yves
last_name: Dubief
- first_name: Vincent E.
full_name: Terrapon, Vincent E.
last_name: Terrapon
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Dubief Y, Terrapon VE, Hof B. Elasto-inertial turbulence. Annual Review
of Fluid Mechanics. 2023;55(1):675-705. doi:10.1146/annurev-fluid-032822-025933
apa: Dubief, Y., Terrapon, V. E., & Hof, B. (2023). Elasto-inertial turbulence.
Annual Review of Fluid Mechanics. Annual Reviews. https://doi.org/10.1146/annurev-fluid-032822-025933
chicago: Dubief, Yves, Vincent E. Terrapon, and Björn Hof. “Elasto-Inertial Turbulence.”
Annual Review of Fluid Mechanics. Annual Reviews, 2023. https://doi.org/10.1146/annurev-fluid-032822-025933.
ieee: Y. Dubief, V. E. Terrapon, and B. Hof, “Elasto-inertial turbulence,” Annual
Review of Fluid Mechanics, vol. 55, no. 1. Annual Reviews, pp. 675–705, 2023.
ista: Dubief Y, Terrapon VE, Hof B. 2023. Elasto-inertial turbulence. Annual Review
of Fluid Mechanics. 55(1), 675–705.
mla: Dubief, Yves, et al. “Elasto-Inertial Turbulence.” Annual Review of Fluid
Mechanics, vol. 55, no. 1, Annual Reviews, 2023, pp. 675–705, doi:10.1146/annurev-fluid-032822-025933.
short: Y. Dubief, V.E. Terrapon, B. Hof, Annual Review of Fluid Mechanics 55 (2023)
675–705.
date_created: 2023-02-26T23:01:01Z
date_published: 2023-01-19T00:00:00Z
date_updated: 2023-08-01T13:19:47Z
day: '19'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1146/annurev-fluid-032822-025933
external_id:
isi:
- '000915418100026'
file:
- access_level: open_access
checksum: 2666aa3af2a25252d35eb8681d3edff7
content_type: application/pdf
creator: dernst
date_created: 2023-02-27T09:23:02Z
date_updated: 2023-02-27T09:23:02Z
file_id: '12690'
file_name: 2023_AnnReviewFluidMech_Dubief.pdf
file_size: 4036706
relation: main_file
success: 1
file_date_updated: 2023-02-27T09:23:02Z
has_accepted_license: '1'
intvolume: ' 55'
isi: 1
issue: '1'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
page: 675-705
publication: Annual Review of Fluid Mechanics
publication_identifier:
eissn:
- 1545-4479
issn:
- 0066-4189
publication_status: published
publisher: Annual Reviews
quality_controlled: '1'
scopus_import: '1'
status: public
title: Elasto-inertial 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: 55
year: '2023'
...
---
_id: '12682'
abstract:
- lang: eng
text: 'Since the seminal studies by Osborne Reynolds in the nineteenth century,
pipe flow has served as a primary prototype for investigating the transition to
turbulence in wall-bounded flows. Despite the apparent simplicity of this flow,
various facets of this problem have occupied researchers for more than a century.
Here we review insights from three distinct perspectives: (a) stability and susceptibility
of laminar flow, (b) phase transition and spatiotemporal dynamics, and (c) dynamical
systems analysis of the Navier—Stokes equations. We show how these perspectives
have led to a profound understanding of the onset of turbulence in pipe flow.
Outstanding open points, applications to flows of complex fluids, and similarities
with other wall-bounded flows are discussed.'
acknowledgement: 'The authors are very grateful to Laurette Tuckerman for her helpful
comments. This work was supported by grants from the Simons Foundation (grant numbers
662985, D.B., and 662960, B.H.) and the Priority Programme “SPP 1881: Turbulent
Superstructures” of the Deutsche Forschungsgemeinschaft (grant number AV120/3-2
to M.A.).'
article_processing_charge: No
article_type: original
author:
- first_name: Marc
full_name: Avila, Marc
last_name: Avila
- first_name: Dwight
full_name: Barkley, Dwight
last_name: Barkley
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Avila M, Barkley D, Hof B. Transition to turbulence in pipe flow. Annual
Review of Fluid Mechanics. 2023;55:575-602. doi:10.1146/annurev-fluid-120720-025957
apa: Avila, M., Barkley, D., & Hof, B. (2023). Transition to turbulence in pipe
flow. Annual Review of Fluid Mechanics. Annual Reviews. https://doi.org/10.1146/annurev-fluid-120720-025957
chicago: Avila, Marc, Dwight Barkley, and Björn Hof. “Transition to Turbulence in
Pipe Flow.” Annual Review of Fluid Mechanics. Annual Reviews, 2023. https://doi.org/10.1146/annurev-fluid-120720-025957.
ieee: M. Avila, D. Barkley, and B. Hof, “Transition to turbulence in pipe flow,”
Annual Review of Fluid Mechanics, vol. 55. Annual Reviews, pp. 575–602,
2023.
ista: Avila M, Barkley D, Hof B. 2023. Transition to turbulence in pipe flow. Annual
Review of Fluid Mechanics. 55, 575–602.
mla: Avila, Marc, et al. “Transition to Turbulence in Pipe Flow.” Annual Review
of Fluid Mechanics, vol. 55, Annual Reviews, 2023, pp. 575–602, doi:10.1146/annurev-fluid-120720-025957.
short: M. Avila, D. Barkley, B. Hof, Annual Review of Fluid Mechanics 55 (2023)
575–602.
date_created: 2023-02-26T23:01:01Z
date_published: 2023-01-19T00:00:00Z
date_updated: 2023-08-01T13:20:30Z
day: '19'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1146/annurev-fluid-120720-025957
external_id:
isi:
- '000915418100023'
file:
- access_level: open_access
checksum: f99ef30f76cabc9e5e1946b380c16db4
content_type: application/pdf
creator: dernst
date_created: 2023-02-27T09:35:52Z
date_updated: 2023-02-27T09:35:52Z
file_id: '12691'
file_name: 2023_AnnReviewFluidMech_Avila.pdf
file_size: 4769537
relation: main_file
success: 1
file_date_updated: 2023-02-27T09:35:52Z
has_accepted_license: '1'
intvolume: ' 55'
isi: 1
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
page: 575-602
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: Annual Review of Fluid Mechanics
publication_identifier:
issn:
- 0066-4189
publication_status: published
publisher: Annual Reviews
quality_controlled: '1'
scopus_import: '1'
status: public
title: Transition to turbulence in pipe 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: 55
year: '2023'
...
---
_id: '12172'
abstract:
- lang: eng
text: In industrial reactors and equipment, non-ideality is quite a common phenomenon
rather than an exception. These deviations from ideality impact the process's
overall efficiency and the effectiveness of the equipment. To recognize the associated
non-ideality, one needs to have enough understanding of the formulation of the
equations and in-depth knowledge of the residence time distribution (RTD) data
of real reactors. In the current work, step input and pulse input were used to
create RTD data for Cascade continuous stirred tank reactors (CSTRs). For the
aforementioned configuration, experiments were run at various flow rates to validate
the developed characteristic equations. To produce RTD data, distilled water was
utilized as the flowing fluid, and NaOH was the tracer substance. The ideal behavior
of tracer concentration exits age distribution, and cumulative fraction for each
setup and each input was plotted and experimental results were compared with perfect
behavior. Deviation of concentration exit age distribution and cumulative fractional
distribution from ideal behavior is more in pulse input as compared to a step
input. For ideal cases, the exit age distribution curve and cumulative fraction
curves are independent of the type of input. But a significant difference was
observed for the two cases, which may be due to non-measurable fluctuations in
volumetric flow rate, non-achievement of instant injection of tracer in case of
pulse input, and slight variations in the sampling period. Further, with increasing
flow rate, concentration, exit age, and cumulative fractional curves shifted upward,
and this behavior matches with the actual case.
article_processing_charge: No
article_type: original
author:
- first_name: Bushra
full_name: Khatoon, Bushra
last_name: Khatoon
- first_name: Shoaib
full_name: Kamil, Shoaib
id: 185a19af-dc7d-11ea-9b2f-8eb2201959e9
last_name: Kamil
- first_name: Hitesh
full_name: Babu, Hitesh
last_name: Babu
- first_name: M.
full_name: Siraj Alam, M.
last_name: Siraj Alam
citation:
ama: 'Khatoon B, Kamil S, Babu H, Siraj Alam M. Experimental analysis of Cascade
CSTRs with step and pulse inputs. Materials Today: Proceedings. 2023;78(Part
1):40-47. doi:10.1016/j.matpr.2022.11.037'
apa: 'Khatoon, B., Kamil, S., Babu, H., & Siraj Alam, M. (2023). Experimental
analysis of Cascade CSTRs with step and pulse inputs. Materials Today: Proceedings.
Elsevier. https://doi.org/10.1016/j.matpr.2022.11.037'
chicago: 'Khatoon, Bushra, Shoaib Kamil, Hitesh Babu, and M. Siraj Alam. “Experimental
Analysis of Cascade CSTRs with Step and Pulse Inputs.” Materials Today: Proceedings.
Elsevier, 2023. https://doi.org/10.1016/j.matpr.2022.11.037.'
ieee: 'B. Khatoon, S. Kamil, H. Babu, and M. Siraj Alam, “Experimental analysis
of Cascade CSTRs with step and pulse inputs,” Materials Today: Proceedings,
vol. 78, no. Part 1. Elsevier, pp. 40–47, 2023.'
ista: 'Khatoon B, Kamil S, Babu H, Siraj Alam M. 2023. Experimental analysis of
Cascade CSTRs with step and pulse inputs. Materials Today: Proceedings. 78(Part
1), 40–47.'
mla: 'Khatoon, Bushra, et al. “Experimental Analysis of Cascade CSTRs with Step
and Pulse Inputs.” Materials Today: Proceedings, vol. 78, no. Part 1, Elsevier,
2023, pp. 40–47, doi:10.1016/j.matpr.2022.11.037.'
short: 'B. Khatoon, S. Kamil, H. Babu, M. Siraj Alam, Materials Today: Proceedings
78 (2023) 40–47.'
date_created: 2023-01-12T12:11:26Z
date_published: 2023-03-20T00:00:00Z
date_updated: 2023-08-16T09:08:11Z
day: '20'
department:
- _id: BjHo
doi: 10.1016/j.matpr.2022.11.037
intvolume: ' 78'
issue: Part 1
keyword:
- General Medicine
language:
- iso: eng
month: '03'
oa_version: None
page: 40-47
publication: 'Materials Today: Proceedings'
publication_identifier:
issn:
- 2214-7853
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: Experimental analysis of Cascade CSTRs with step and pulse inputs
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 78
year: '2023'
...