---
_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.
corr_author: '1'
date_created: 2018-12-11T11:46:23Z
date_published: 2018-01-01T00:00:00Z
date_updated: 2026-08-13T22:30:26Z
day: '01'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1007/s10494-018-9896-4
ec_funded: 1
external_id:
  isi:
  - '000433113900004'
file:
- access_level: open_access
  checksum: d7c0bade150faabca150b0a9986e60ca
  content_type: application/pdf
  creator: dernst
  date_created: 2018-12-17T15:52:37Z
  date_updated: 2020-07-14T12:46:25Z
  file_id: '5717'
  file_name: 2018_FlowTurbulenceCombust_Kuehnen.pdf
  file_size: 2210020
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file_date_updated: 2020-07-14T12:46:25Z
has_accepted_license: '1'
intvolume: '       100'
isi: 1
issue: '4'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '01'
oa: 1
oa_version: Published Version
page: 919 - 942
project:
- _id: 25152F3A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '306589'
  name: Decoding the complexity of turbulence at its origin
publication: Flow Turbulence and Combustion
publication_status: published
publisher: Springer
publist_id: '7401'
quality_controlled: '1'
related_material:
  record:
  - id: '7258'
    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: Relaminarization by steady modification of the streamwise velocity profile
  in a pipe
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: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 100
year: '2018'
...