---
_id: '14341'
abstract:
- lang: eng
  text: Flows through pipes and channels are, in practice, almost always turbulent,
    and the multiscale eddying motion is responsible for a major part of the encountered
    friction losses and pumping costs1. Conversely, for pulsatile flows, in particular
    for aortic blood flow, turbulence levels remain low despite relatively large peak
    velocities. For aortic blood flow, high turbulence levels are intolerable as they
    would damage the shear-sensitive endothelial cell layer2,3,4,5. Here we show that
    turbulence in ordinary pipe flow is diminished if the flow is driven in a pulsatile
    mode that incorporates all the key features of the cardiac waveform. At Reynolds
    numbers comparable to those of aortic blood flow, turbulence is largely inhibited,
    whereas at much higher speeds, the turbulent drag is reduced by more than 25%.
    This specific operation mode is more efficient when compared with steady driving,
    which is the present situation for virtually all fluid transport processes ranging
    from heating circuits to water, gas and oil pipelines.
acknowledged_ssus:
- _id: M-Shop
- _id: ScienComp
acknowledgement: We acknowledge the assistance of the Miba machine shop and the team
  of the ISTA-HPC cluster. We thank M. Quadrio for the discussions. The work was supported
  by the Simons Foundation (grant no. 662960) and by the Austrian Science Fund (grant
  no. I4188-N30), within Deutsche Forschungsgemeinschaft research unit FOR 2688.
article_processing_charge: No
article_type: original
author:
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- 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: Atul
  full_name: Varshney, Atul
  id: 2A2006B2-F248-11E8-B48F-1D18A9856A87
  last_name: Varshney
  orcid: 0000-0002-3072-5999
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Scarselli D, Lopez Alonso JM, Varshney A, Hof B. Turbulence suppression by
    cardiac-cycle-inspired driving of pipe flow. <i>Nature</i>. 2023;621(7977):71-74.
    doi:<a href="https://doi.org/10.1038/s41586-023-06399-5">10.1038/s41586-023-06399-5</a>
  apa: Scarselli, D., Lopez Alonso, J. M., Varshney, A., &#38; Hof, B. (2023). Turbulence
    suppression by cardiac-cycle-inspired driving of pipe flow. <i>Nature</i>. Springer
    Nature. <a href="https://doi.org/10.1038/s41586-023-06399-5">https://doi.org/10.1038/s41586-023-06399-5</a>
  chicago: Scarselli, Davide, Jose M Lopez Alonso, Atul Varshney, and Björn Hof. “Turbulence
    Suppression by Cardiac-Cycle-Inspired Driving of Pipe Flow.” <i>Nature</i>. Springer
    Nature, 2023. <a href="https://doi.org/10.1038/s41586-023-06399-5">https://doi.org/10.1038/s41586-023-06399-5</a>.
  ieee: D. Scarselli, J. M. Lopez Alonso, A. Varshney, and B. Hof, “Turbulence suppression
    by cardiac-cycle-inspired driving of pipe flow,” <i>Nature</i>, vol. 621, no.
    7977. Springer Nature, pp. 71–74, 2023.
  ista: Scarselli D, Lopez Alonso JM, Varshney A, Hof B. 2023. Turbulence suppression
    by cardiac-cycle-inspired driving of pipe flow. Nature. 621(7977), 71–74.
  mla: Scarselli, Davide, et al. “Turbulence Suppression by Cardiac-Cycle-Inspired
    Driving of Pipe Flow.” <i>Nature</i>, vol. 621, no. 7977, Springer Nature, 2023,
    pp. 71–74, doi:<a href="https://doi.org/10.1038/s41586-023-06399-5">10.1038/s41586-023-06399-5</a>.
  short: D. Scarselli, J.M. Lopez Alonso, A. Varshney, B. Hof, Nature 621 (2023) 71–74.
date_created: 2023-09-17T22:01:09Z
date_published: 2023-09-07T00:00:00Z
date_updated: 2023-09-20T12:10:22Z
day: '07'
department:
- _id: BjHo
doi: 10.1038/s41586-023-06399-5
external_id:
  pmid:
  - '37673988'
intvolume: '       621'
issue: '7977'
language:
- iso: eng
month: '09'
oa_version: None
page: 71-74
pmid: 1
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'
- _id: 238B8092-32DE-11EA-91FC-C7463DDC885E
  call_identifier: FWF
  grant_number: I04188
  name: Instabilities in pulsating pipe flow of Newtonian and complex fluids
publication: Nature
publication_identifier:
  eissn:
  - 1476-4687
  issn:
  - 0028-0836
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  link:
  - description: News on ISTA website
    relation: press_release
    url: https://www.ista.ac.at/en/news/pumping-like-the-heart/
scopus_import: '1'
status: public
title: Turbulence suppression by cardiac-cycle-inspired driving of pipe flow
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 621
year: '2023'
...
---
_id: '12134'
abstract:
- lang: eng
  text: Standard epidemic models exhibit one continuous, second order phase transition
    to macroscopic outbreaks. However, interventions to control outbreaks may fundamentally
    alter epidemic dynamics. Here we reveal how such interventions modify the type
    of phase transition. In particular, we uncover three distinct types of explosive
    phase transitions for epidemic dynamics with capacity-limited interventions. Depending
    on the capacity limit, interventions may (i) leave the standard second order phase
    transition unchanged but exponentially suppress the probability of large outbreaks,
    (ii) induce a first-order discontinuous transition to macroscopic outbreaks, or
    (iii) cause a secondary explosive yet continuous third-order transition. These
    insights highlight inherent limitations in predicting and containing epidemic
    outbreaks. More generally our study offers a cornerstone example of a third-order
    explosive phase transition in complex systems.
acknowledgement: We acknowledge support from the Volkswagen Foundation under Grant
  No. 99720 and the German Federal Ministry for Education and Research (BMBF) under
  Grant No. 16ICR01. This research was supported by the Deutsche Forschungsgemeinschaft
  (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC-2068—390729961—Cluster
  of Excellence Physics of Life of TU Dresden.
article_number: 04LT02
article_processing_charge: No
article_type: original
author:
- first_name: Georg
  full_name: Börner, Georg
  last_name: Börner
- first_name: Malte
  full_name: Schröder, Malte
  last_name: Schröder
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Nazmi B
  full_name: Budanur, Nazmi B
  id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
  last_name: Budanur
  orcid: 0000-0003-0423-5010
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
- first_name: Marc
  full_name: Timme, Marc
  last_name: Timme
citation:
  ama: 'Börner G, Schröder M, Scarselli D, Budanur NB, Hof B, Timme M. Explosive transitions
    in epidemic dynamics. <i>Journal of Physics: Complexity</i>. 2022;3(4). doi:<a
    href="https://doi.org/10.1088/2632-072x/ac99cd">10.1088/2632-072x/ac99cd</a>'
  apa: 'Börner, G., Schröder, M., Scarselli, D., Budanur, N. B., Hof, B., &#38; Timme,
    M. (2022). Explosive transitions in epidemic dynamics. <i>Journal of Physics:
    Complexity</i>. IOP Publishing. <a href="https://doi.org/10.1088/2632-072x/ac99cd">https://doi.org/10.1088/2632-072x/ac99cd</a>'
  chicago: 'Börner, Georg, Malte Schröder, Davide Scarselli, Nazmi B Budanur, Björn
    Hof, and Marc Timme. “Explosive Transitions in Epidemic Dynamics.” <i>Journal
    of Physics: Complexity</i>. IOP Publishing, 2022. <a href="https://doi.org/10.1088/2632-072x/ac99cd">https://doi.org/10.1088/2632-072x/ac99cd</a>.'
  ieee: 'G. Börner, M. Schröder, D. Scarselli, N. B. Budanur, B. Hof, and M. Timme,
    “Explosive transitions in epidemic dynamics,” <i>Journal of Physics: Complexity</i>,
    vol. 3, no. 4. IOP Publishing, 2022.'
  ista: 'Börner G, Schröder M, Scarselli D, Budanur NB, Hof B, Timme M. 2022. Explosive
    transitions in epidemic dynamics. Journal of Physics: Complexity. 3(4), 04LT02.'
  mla: 'Börner, Georg, et al. “Explosive Transitions in Epidemic Dynamics.” <i>Journal
    of Physics: Complexity</i>, vol. 3, no. 4, 04LT02, IOP Publishing, 2022, doi:<a
    href="https://doi.org/10.1088/2632-072x/ac99cd">10.1088/2632-072x/ac99cd</a>.'
  short: 'G. Börner, M. Schröder, D. Scarselli, N.B. Budanur, B. Hof, M. Timme, Journal
    of Physics: Complexity 3 (2022).'
date_created: 2023-01-12T12:03:43Z
date_published: 2022-10-25T00:00:00Z
date_updated: 2023-02-13T09:15:13Z
day: '25'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1088/2632-072x/ac99cd
file:
- access_level: open_access
  checksum: 35c5c5cb0eb17ea1b5184755daab9fc9
  content_type: application/pdf
  creator: dernst
  date_created: 2023-01-24T07:24:37Z
  date_updated: 2023-01-24T07:24:37Z
  file_id: '12350'
  file_name: 2022_JourPhysics_Boerner.pdf
  file_size: 1006106
  relation: main_file
  success: 1
file_date_updated: 2023-01-24T07:24:37Z
has_accepted_license: '1'
intvolume: '         3'
issue: '4'
keyword:
- Artificial Intelligence
- Computer Networks and Communications
- Computer Science Applications
- Information Systems
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: 'Journal of Physics: Complexity'
publication_identifier:
  issn:
  - 2632-072X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Explosive transitions in epidemic dynamics
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: 3
year: '2022'
...
---
_id: '9407'
abstract:
- lang: eng
  text: 'High impact epidemics constitute one of the largest threats humanity is facing
    in the 21st century. In the absence of pharmaceutical interventions, physical
    distancing together with testing, contact tracing and quarantining are crucial
    in slowing down epidemic dynamics. Yet, here we show that if testing capacities
    are limited, containment may fail dramatically because such combined countermeasures
    drastically change the rules of the epidemic transition: Instead of continuous,
    the response to countermeasures becomes discontinuous. Rather than following the
    conventional exponential growth, the outbreak that is initially strongly suppressed
    eventually accelerates and scales faster than exponential during an explosive
    growth period. As a consequence, containment measures either suffice to stop the
    outbreak at low total case numbers or fail catastrophically if marginally too
    weak, thus implying large uncertainties in reliably estimating overall epidemic
    dynamics, both during initial phases and during second wave scenarios.'
acknowledgement: The authors thank Malte Schröder for valuable discussions and creating
  the scale-free network topologies. B.H. thanks Mukund Vasudevan for helpful discussion.
  The research by M.T. was supported by the Deutsche Forschungsgemeinschaft (DFG,
  German Research Foundation) under Germany´s Excellence Strategy–EXC-2068–390729961–Cluster
  of Excellence Physics of Life of TU Dresden.
article_number: '2586'
article_processing_charge: No
article_type: original
author:
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Nazmi B
  full_name: Budanur, Nazmi B
  id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
  last_name: Budanur
  orcid: 0000-0003-0423-5010
- first_name: Marc
  full_name: Timme, Marc
  last_name: Timme
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Scarselli D, Budanur NB, Timme M, Hof B. Discontinuous epidemic transition
    due to limited testing. <i>Nature Communications</i>. 2021;12(1). doi:<a href="https://doi.org/10.1038/s41467-021-22725-9">10.1038/s41467-021-22725-9</a>
  apa: Scarselli, D., Budanur, N. B., Timme, M., &#38; Hof, B. (2021). Discontinuous
    epidemic transition due to limited testing. <i>Nature Communications</i>. Springer
    Nature. <a href="https://doi.org/10.1038/s41467-021-22725-9">https://doi.org/10.1038/s41467-021-22725-9</a>
  chicago: Scarselli, Davide, Nazmi B Budanur, Marc Timme, and Björn Hof. “Discontinuous
    Epidemic Transition Due to Limited Testing.” <i>Nature Communications</i>. Springer
    Nature, 2021. <a href="https://doi.org/10.1038/s41467-021-22725-9">https://doi.org/10.1038/s41467-021-22725-9</a>.
  ieee: D. Scarselli, N. B. Budanur, M. Timme, and B. Hof, “Discontinuous epidemic
    transition due to limited testing,” <i>Nature Communications</i>, vol. 12, no.
    1. Springer Nature, 2021.
  ista: Scarselli D, Budanur NB, Timme M, Hof B. 2021. Discontinuous epidemic transition
    due to limited testing. Nature Communications. 12(1), 2586.
  mla: Scarselli, Davide, et al. “Discontinuous Epidemic Transition Due to Limited
    Testing.” <i>Nature Communications</i>, vol. 12, no. 1, 2586, Springer Nature,
    2021, doi:<a href="https://doi.org/10.1038/s41467-021-22725-9">10.1038/s41467-021-22725-9</a>.
  short: D. Scarselli, N.B. Budanur, M. Timme, B. Hof, Nature Communications 12 (2021).
date_created: 2021-05-23T22:01:42Z
date_published: 2021-05-10T00:00:00Z
date_updated: 2023-08-08T13:45:13Z
day: '10'
ddc:
- '570'
department:
- _id: BjHo
doi: 10.1038/s41467-021-22725-9
external_id:
  isi:
  - '000687305500044'
file:
- access_level: open_access
  checksum: fe26c1b8a7da1ae07a6c03f80ff06ea1
  content_type: application/pdf
  creator: kschuh
  date_created: 2021-05-25T14:18:40Z
  date_updated: 2021-05-25T14:18:40Z
  file_id: '9426'
  file_name: 2021_NatureCommunications_Scarselli.pdf
  file_size: 1176573
  relation: main_file
  success: 1
file_date_updated: 2021-05-25T14:18:40Z
has_accepted_license: '1'
intvolume: '        12'
isi: 1
issue: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: Nature Communications
publication_identifier:
  eissn:
  - '20411723'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  link:
  - description: News on IST Homepage
    relation: press_release
    url: https://ist.ac.at/en/news/smashing-the-covid-curve/
scopus_import: '1'
status: public
title: Discontinuous epidemic transition due to limited testing
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: 12
year: '2021'
...
---
_id: '7258'
abstract:
- lang: eng
  text: Many flows encountered in nature and applications are characterized by a chaotic
    motion known as turbulence. Turbulent flows generate intense friction with pipe
    walls and are responsible for considerable amounts of energy losses at world scale.
    The nature of turbulent friction and techniques aimed at reducing it have been
    subject of extensive research over the last century, but no definite answer has
    been found yet. In this thesis we show that in pipes at moderate turbulent Reynolds
    numbers friction is better described by the power law first introduced by Blasius
    and not by the Prandtl–von Kármán formula. At higher Reynolds numbers, large scale
    motions gradually become more important in the flow and can be related to the
    change in scaling of friction. Next, we present a series of new techniques that
    can relaminarize turbulence by suppressing a key mechanism that regenerates it
    at walls, the lift–up effect. In addition, we investigate the process of turbulence
    decay in several experiments and discuss the drag reduction potential. Finally,
    we examine the behavior of friction under pulsating conditions inspired by the
    human heart cycle and we show that under such circumstances turbulent friction
    can be reduced to produce energy savings.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
citation:
  ama: Scarselli D. New approaches to reduce friction in turbulent pipe flow. 2020.
    doi:<a href="https://doi.org/10.15479/AT:ISTA:7258">10.15479/AT:ISTA:7258</a>
  apa: Scarselli, D. (2020). <i>New approaches to reduce friction in turbulent pipe
    flow</i>. Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:7258">https://doi.org/10.15479/AT:ISTA:7258</a>
  chicago: Scarselli, Davide. “New Approaches to Reduce Friction in Turbulent Pipe
    Flow.” Institute of Science and Technology Austria, 2020. <a href="https://doi.org/10.15479/AT:ISTA:7258">https://doi.org/10.15479/AT:ISTA:7258</a>.
  ieee: D. Scarselli, “New approaches to reduce friction in turbulent pipe flow,”
    Institute of Science and Technology Austria, 2020.
  ista: Scarselli D. 2020. New approaches to reduce friction in turbulent pipe flow.
    Institute of Science and Technology Austria.
  mla: Scarselli, Davide. <i>New Approaches to Reduce Friction in Turbulent Pipe Flow</i>.
    Institute of Science and Technology Austria, 2020, doi:<a href="https://doi.org/10.15479/AT:ISTA:7258">10.15479/AT:ISTA:7258</a>.
  short: D. Scarselli, New Approaches to Reduce Friction in Turbulent Pipe Flow, Institute
    of Science and Technology Austria, 2020.
date_created: 2020-01-12T16:07:26Z
date_published: 2020-01-13T00:00:00Z
date_updated: 2023-09-15T12:20:08Z
day: '13'
ddc:
- '532'
degree_awarded: PhD
department:
- _id: BjHo
doi: 10.15479/AT:ISTA:7258
ec_funded: 1
file:
- access_level: closed
  checksum: 4df1ab24e9896635106adde5a54615bf
  content_type: application/zip
  creator: dscarsel
  date_created: 2020-01-12T15:57:14Z
  date_updated: 2021-01-13T23:30:05Z
  embargo_to: open_access
  file_id: '7259'
  file_name: 2020_Scarselli_Thesis.zip
  file_size: 26640830
  relation: source_file
- access_level: open_access
  checksum: 48659ab98e3414293c7a721385c2fd1c
  content_type: application/pdf
  creator: dscarsel
  date_created: 2020-01-12T15:56:14Z
  date_updated: 2021-01-13T23:30:05Z
  embargo: 2021-01-12
  file_id: '7260'
  file_name: 2020_Scarselli_Thesis.pdf
  file_size: 8515844
  relation: main_file
file_date_updated: 2021-01-13T23:30:05Z
has_accepted_license: '1'
language:
- iso: eng
month: '01'
oa: 1
oa_version: None
page: '174'
project:
- _id: 25152F3A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '306589'
  name: Decoding the complexity of turbulence at its origin
- _id: 25104D44-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '737549'
  name: Eliminating turbulence in oil pipelines
- _id: 25136C54-B435-11E9-9278-68D0E5697425
  grant_number: HO 4393/1-2
  name: Experimental studies of the turbulence transition and transport processes
    in turbulent Taylor-Couette currents
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '6228'
    relation: part_of_dissertation
    status: public
  - id: '6486'
    relation: part_of_dissertation
    status: public
  - id: '461'
    relation: part_of_dissertation
    status: public
  - id: '422'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
title: New approaches to reduce friction in turbulent pipe flow
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2020'
...
---
_id: '6228'
abstract:
- lang: eng
  text: Following  the  recent  observation  that  turbulent  pipe  flow  can  be  relaminarised  bya  relatively  simple  modification  of  the  mean  velocity  profile,  we  here  carry  out  aquantitative  experimental  investigation  of  this  phenomenon.  Our  study  confirms  thata  flat  velocity  profile  leads  to  a  collapse  of  turbulence  and  in  order  to  achieve  theblunted  profile  shape,  we  employ  a  moving  pipe  segment  that  is  briefly  and  rapidlyshifted  in  the  streamwise  direction.  The  relaminarisation  threshold  and  the  minimumshift  length  and  speeds  are  determined  as  a  function  of  Reynolds  number.  Althoughturbulence  is  still  active  after  the  acceleration  phase,  the  modulated  profile  possessesa  severely  decreased  lift-up  potential  as  measured  by  transient  growth.  As  shown,this  results  in  an  exponential  decay  of  fluctuations  and  the  flow  relaminarises.  Whilethis  method  can  be  easily  applied  at  low  to  moderate  flow  speeds,  the  minimumstreamwise  length  over  which  the  acceleration  needs  to  act  increases  linearly  with  theReynolds  number.
article_processing_charge: No
arxiv: 1
author:
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Jakob
  full_name: Kühnen, Jakob
  id: 3A47AE32-F248-11E8-B48F-1D18A9856A87
  last_name: Kühnen
  orcid: 0000-0003-4312-0179
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Scarselli D, Kühnen J, Hof B. Relaminarising pipe flow by wall movement. <i>Journal
    of Fluid Mechanics</i>. 2019;867:934-948. doi:<a href="https://doi.org/10.1017/jfm.2019.191">10.1017/jfm.2019.191</a>
  apa: Scarselli, D., Kühnen, J., &#38; Hof, B. (2019). Relaminarising pipe flow by
    wall movement. <i>Journal of Fluid Mechanics</i>. Cambridge University Press.
    <a href="https://doi.org/10.1017/jfm.2019.191">https://doi.org/10.1017/jfm.2019.191</a>
  chicago: Scarselli, Davide, Jakob Kühnen, and Björn Hof. “Relaminarising Pipe Flow
    by Wall Movement.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press,
    2019. <a href="https://doi.org/10.1017/jfm.2019.191">https://doi.org/10.1017/jfm.2019.191</a>.
  ieee: D. Scarselli, J. Kühnen, and B. Hof, “Relaminarising pipe flow by wall movement,”
    <i>Journal of Fluid Mechanics</i>, vol. 867. Cambridge University Press, pp. 934–948,
    2019.
  ista: Scarselli D, Kühnen J, Hof B. 2019. Relaminarising pipe flow by wall movement.
    Journal of Fluid Mechanics. 867, 934–948.
  mla: Scarselli, Davide, et al. “Relaminarising Pipe Flow by Wall Movement.” <i>Journal
    of Fluid Mechanics</i>, vol. 867, Cambridge University Press, 2019, pp. 934–48,
    doi:<a href="https://doi.org/10.1017/jfm.2019.191">10.1017/jfm.2019.191</a>.
  short: D. Scarselli, J. Kühnen, B. Hof, Journal of Fluid Mechanics 867 (2019) 934–948.
date_created: 2019-04-07T21:59:14Z
date_published: 2019-05-25T00:00:00Z
date_updated: 2024-03-25T23:30:20Z
day: '25'
department:
- _id: BjHo
doi: 10.1017/jfm.2019.191
ec_funded: 1
external_id:
  arxiv:
  - '1807.05357'
  isi:
  - '000462606100001'
intvolume: '       867'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1807.05357
month: '05'
oa: 1
oa_version: Preprint
page: 934-948
project:
- _id: 25152F3A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '306589'
  name: Decoding the complexity of turbulence at its origin
- _id: 25104D44-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '737549'
  name: Eliminating turbulence in oil pipelines
publication: Journal of Fluid Mechanics
publication_identifier:
  eissn:
  - '14697645'
  issn:
  - '00221120'
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
related_material:
  link:
  - relation: supplementary_material
    url: https://doi.org/10.1017/jfm.2019.191
  record:
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    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: Relaminarising pipe flow by wall movement
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 867
year: '2019'
...
---
_id: '6486'
abstract:
- lang: eng
  text: Based on a novel control scheme, where a steady modification of the streamwise
    velocity profile leads to complete relaminarization of initially fully turbulent
    pipe flow, we investigate the applicability and usefulness of custom-shaped honeycombs
    for such control. The custom-shaped honeycombs are used as stationary flow management
    devices which generate specific modifications of the streamwise velocity profile.
    Stereoscopic particle image velocimetry and pressure drop measurements are used
    to investigate and capture the development of the relaminarizing flow downstream
    these devices. We compare the performance of straight (constant length across
    the radius of the pipe) honeycombs with custom-shaped ones (variable length across
    the radius) and try to determine the optimal shape for maximal relaminarization
    at minimal pressure loss. The optimally modified streamwise velocity profile is
    found to be M-shaped, and the maximum attainable Reynolds number for total relaminarization
    is found to be of the order of 10,000. Consequently, the respective reduction
    in skin friction downstream of the device is almost by a factor of 5. The break-even
    point, where the additional pressure drop caused by the device is balanced by
    the savings due to relaminarization and a net gain is obtained, corresponds to
    a downstream stretch of distances as low as approximately 100 pipe diameters of
    laminar flow.
acknowledged_ssus:
- _id: M-Shop
article_number: '111105'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jakob
  full_name: Kühnen, Jakob
  id: 3A47AE32-F248-11E8-B48F-1D18A9856A87
  last_name: Kühnen
  orcid: 0000-0003-4312-0179
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Kühnen J, Scarselli D, Hof B. Relaminarization of pipe flow by means of 3D-printed
    shaped honeycombs. <i>Journal of Fluids Engineering</i>. 2019;141(11). doi:<a
    href="https://doi.org/10.1115/1.4043494">10.1115/1.4043494</a>
  apa: Kühnen, J., Scarselli, D., &#38; Hof, B. (2019). Relaminarization of pipe flow
    by means of 3D-printed shaped honeycombs. <i>Journal of Fluids Engineering</i>.
    ASME. <a href="https://doi.org/10.1115/1.4043494">https://doi.org/10.1115/1.4043494</a>
  chicago: Kühnen, Jakob, Davide Scarselli, and Björn Hof. “Relaminarization of Pipe
    Flow by Means of 3D-Printed Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>.
    ASME, 2019. <a href="https://doi.org/10.1115/1.4043494">https://doi.org/10.1115/1.4043494</a>.
  ieee: J. Kühnen, D. Scarselli, and B. Hof, “Relaminarization of pipe flow by means
    of 3D-printed shaped honeycombs,” <i>Journal of Fluids Engineering</i>, vol. 141,
    no. 11. ASME, 2019.
  ista: Kühnen J, Scarselli D, Hof B. 2019. Relaminarization of pipe flow by means
    of 3D-printed shaped honeycombs. Journal of Fluids Engineering. 141(11), 111105.
  mla: Kühnen, Jakob, et al. “Relaminarization of Pipe Flow by Means of 3D-Printed
    Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>, vol. 141, no. 11, 111105,
    ASME, 2019, doi:<a href="https://doi.org/10.1115/1.4043494">10.1115/1.4043494</a>.
  short: J. Kühnen, D. Scarselli, B. Hof, Journal of Fluids Engineering 141 (2019).
date_created: 2019-05-26T21:59:13Z
date_published: 2019-11-01T00:00:00Z
date_updated: 2024-03-25T23:30:20Z
day: '01'
department:
- _id: BjHo
doi: 10.1115/1.4043494
ec_funded: 1
external_id:
  arxiv:
  - '1809.07625'
  isi:
  - '000487748600005'
intvolume: '       141'
isi: 1
issue: '11'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1809.07625
month: '11'
oa: 1
oa_version: Preprint
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 Fluids Engineering
publication_identifier:
  eissn:
  - 1528901X
  issn:
  - '00982202'
publication_status: published
publisher: ASME
quality_controlled: '1'
related_material:
  record:
  - id: '7258'
    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: Relaminarization of pipe flow by means of 3D-printed shaped honeycombs
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 141
year: '2019'
...
---
_id: '461'
abstract:
- lang: eng
  text: Turbulence is the major cause of friction losses in transport processes and
    it is responsible for a drastic drag increase in flows over bounding surfaces.
    While much effort is invested into developing ways to control and reduce turbulence
    intensities, so far no methods exist to altogether eliminate turbulence if velocities
    are sufficiently large. We demonstrate for pipe flow that appropriate distortions
    to the velocity profile lead to a complete collapse of turbulence and subsequently
    friction losses are reduced by as much as 90%. Counterintuitively, the return
    to laminar motion is accomplished by initially increasing turbulence intensities
    or by transiently amplifying wall shear. Since neither the Reynolds number nor
    the shear stresses decrease (the latter often increase), these measures are not
    indicative of turbulence collapse. Instead, an amplification mechanism                      measuring
    the interaction between eddies and the mean shear is found to set a threshold
    below which turbulence is suppressed beyond recovery.
acknowledgement: We acknowledge the European Research Council under the European Union’s
  Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement 306589, the European
  Research Council (ERC) under the European Union’s Horizon 2020 research and innovation
  programme (grant agreement no. 737549) and the Deutsche Forschungsgemeinschaft (Project
  No. FOR 1182) for financial support. We thank our technician P. Maier for providing
  highly valuable ideas and greatly supporting us in all technical aspects. We thank
  M. Schaner for technical drawings, construction and design. We thank M. Schwegel
  for a Matlab code to post-process experimental data.
article_processing_charge: No
author:
- first_name: Jakob
  full_name: Kühnen, Jakob
  id: 3A47AE32-F248-11E8-B48F-1D18A9856A87
  last_name: Kühnen
  orcid: 0000-0003-4312-0179
- first_name: Baofang
  full_name: Song, Baofang
  last_name: Song
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Nazmi B
  full_name: Budanur, Nazmi B
  id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
  last_name: Budanur
  orcid: 0000-0003-0423-5010
- first_name: Michael
  full_name: Riedl, Michael
  id: 3BE60946-F248-11E8-B48F-1D18A9856A87
  last_name: Riedl
  orcid: 0000-0003-4844-6311
- first_name: Ashley
  full_name: Willis, Ashley
  last_name: Willis
- first_name: Marc
  full_name: Avila, Marc
  last_name: Avila
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Kühnen J, Song B, Scarselli D, et al. Destabilizing turbulence in pipe flow.
    <i>Nature Physics</i>. 2018;14:386-390. doi:<a href="https://doi.org/10.1038/s41567-017-0018-3">10.1038/s41567-017-0018-3</a>
  apa: Kühnen, J., Song, B., Scarselli, D., Budanur, N. B., Riedl, M., Willis, A.,
    … Hof, B. (2018). Destabilizing turbulence in pipe flow. <i>Nature Physics</i>.
    Nature Publishing Group. <a href="https://doi.org/10.1038/s41567-017-0018-3">https://doi.org/10.1038/s41567-017-0018-3</a>
  chicago: Kühnen, Jakob, Baofang Song, Davide Scarselli, Nazmi B Budanur, Michael
    Riedl, Ashley Willis, Marc Avila, and Björn Hof. “Destabilizing Turbulence in
    Pipe Flow.” <i>Nature Physics</i>. Nature Publishing Group, 2018. <a href="https://doi.org/10.1038/s41567-017-0018-3">https://doi.org/10.1038/s41567-017-0018-3</a>.
  ieee: J. Kühnen <i>et al.</i>, “Destabilizing turbulence in pipe flow,” <i>Nature
    Physics</i>, vol. 14. Nature Publishing Group, pp. 386–390, 2018.
  ista: Kühnen J, Song B, Scarselli D, Budanur NB, Riedl M, Willis A, Avila M, Hof
    B. 2018. Destabilizing turbulence in pipe flow. Nature Physics. 14, 386–390.
  mla: Kühnen, Jakob, et al. “Destabilizing Turbulence in Pipe Flow.” <i>Nature Physics</i>,
    vol. 14, Nature Publishing Group, 2018, pp. 386–90, doi:<a href="https://doi.org/10.1038/s41567-017-0018-3">10.1038/s41567-017-0018-3</a>.
  short: J. Kühnen, B. Song, D. Scarselli, N.B. Budanur, M. Riedl, A. Willis, M. Avila,
    B. Hof, Nature Physics 14 (2018) 386–390.
date_created: 2018-12-11T11:46:36Z
date_published: 2018-01-08T00:00:00Z
date_updated: 2024-03-25T23:30:20Z
day: '08'
department:
- _id: BjHo
doi: 10.1038/s41567-017-0018-3
ec_funded: 1
external_id:
  isi:
  - '000429434100020'
intvolume: '        14'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1711.06543
month: '01'
oa: 1
oa_version: Preprint
page: 386-390
project:
- _id: 25152F3A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '306589'
  name: Decoding the complexity of turbulence at its origin
- _id: 25104D44-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '737549'
  name: Eliminating turbulence in oil pipelines
publication: Nature Physics
publication_status: published
publisher: Nature Publishing Group
publist_id: '7360'
quality_controlled: '1'
related_material:
  record:
  - id: '12726'
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    status: public
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    status: public
  - id: '7258'
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    status: public
scopus_import: '1'
status: public
title: Destabilizing turbulence in pipe flow
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 14
year: '2018'
...
---
_id: '422'
abstract:
- lang: eng
  text: We show that a rather simple, steady modification of the streamwise velocity
    profile in a pipe can lead to a complete collapse of turbulence and the flow fully
    relaminarizes. Two different devices, a stationary obstacle (inset) and a device
    which injects fluid through an annular gap close to the wall, are used to control
    the flow. Both devices modify the streamwise velocity profile such that the flow
    in the center of the pipe is decelerated and the flow in the near wall region
    is accelerated. We present measurements with stereoscopic particle image velocimetry
    to investigate and capture the development of the relaminarizing flow downstream
    these devices and the specific circumstances responsible for relaminarization.
    We find total relaminarization up to Reynolds numbers of 6000, where the skin
    friction in the far downstream distance is reduced by a factor of 3.4 due to relaminarization.
    In a smooth straight pipe the flow remains completely laminar downstream of the
    control. Furthermore, we show that transient (temporary) relaminarization in a
    spatially confined region right downstream the devices occurs also at much higher
    Reynolds numbers, accompanied by a significant local skin friction drag reduction.
    The underlying physical mechanism of relaminarization is attributed to a weakening
    of the near-wall turbulence production cycle.
article_processing_charge: Yes (via OA deal)
author:
- first_name: Jakob
  full_name: Kühnen, Jakob
  id: 3A47AE32-F248-11E8-B48F-1D18A9856A87
  last_name: Kühnen
  orcid: 0000-0003-4312-0179
- first_name: Davide
  full_name: Scarselli, Davide
  id: 40315C30-F248-11E8-B48F-1D18A9856A87
  last_name: Scarselli
  orcid: 0000-0001-5227-4271
- first_name: Markus
  full_name: Schaner, Markus
  id: 316CE034-F248-11E8-B48F-1D18A9856A87
  last_name: Schaner
- first_name: Björn
  full_name: Hof, Björn
  id: 3A374330-F248-11E8-B48F-1D18A9856A87
  last_name: Hof
  orcid: 0000-0003-2057-2754
citation:
  ama: Kühnen J, Scarselli D, Schaner M, Hof B. Relaminarization by steady modification
    of the streamwise velocity profile in a pipe. <i>Flow Turbulence and Combustion</i>.
    2018;100(4):919-942. doi:<a href="https://doi.org/10.1007/s10494-018-9896-4">10.1007/s10494-018-9896-4</a>
  apa: Kühnen, J., Scarselli, D., Schaner, M., &#38; Hof, B. (2018). Relaminarization
    by steady modification of the streamwise velocity profile in a pipe. <i>Flow Turbulence
    and Combustion</i>. Springer. <a href="https://doi.org/10.1007/s10494-018-9896-4">https://doi.org/10.1007/s10494-018-9896-4</a>
  chicago: Kühnen, Jakob, Davide Scarselli, Markus Schaner, and Björn Hof. “Relaminarization
    by Steady Modification of the Streamwise Velocity Profile in a Pipe.” <i>Flow
    Turbulence and Combustion</i>. Springer, 2018. <a href="https://doi.org/10.1007/s10494-018-9896-4">https://doi.org/10.1007/s10494-018-9896-4</a>.
  ieee: J. Kühnen, D. Scarselli, M. Schaner, and B. Hof, “Relaminarization by steady
    modification of the streamwise velocity profile in a pipe,” <i>Flow Turbulence
    and Combustion</i>, vol. 100, no. 4. Springer, pp. 919–942, 2018.
  ista: Kühnen J, Scarselli D, Schaner M, Hof B. 2018. Relaminarization by steady
    modification of the streamwise velocity profile in a pipe. Flow Turbulence and
    Combustion. 100(4), 919–942.
  mla: Kühnen, Jakob, et al. “Relaminarization by Steady Modification of the Streamwise
    Velocity Profile in a Pipe.” <i>Flow Turbulence and Combustion</i>, vol. 100,
    no. 4, Springer, 2018, pp. 919–42, doi:<a href="https://doi.org/10.1007/s10494-018-9896-4">10.1007/s10494-018-9896-4</a>.
  short: J. Kühnen, D. Scarselli, M. Schaner, B. Hof, Flow Turbulence and Combustion
    100 (2018) 919–942.
date_created: 2018-12-11T11:46:23Z
date_published: 2018-01-01T00:00:00Z
date_updated: 2024-03-25T23:30:20Z
day: '01'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1007/s10494-018-9896-4
ec_funded: 1
external_id:
  isi:
  - '000433113900004'
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  call_identifier: FP7
  grant_number: '306589'
  name: Decoding the complexity of turbulence at its origin
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publisher: Springer
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quality_controlled: '1'
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scopus_import: '1'
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title: Relaminarization by steady modification of the streamwise velocity profile
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