Formation of coherent structures by fluid inertia in three-dimensional laminar flows

Z. Pouransari, M.F.M Speetjens, H.J.H. Clercx

Research output: Contribution to journalArticleAcademicpeer-review

28 Citations (Scopus)

Abstract

Mixing under laminar flow conditions is key to a wide variety of industrial fluid systems of size extending from micrometres to metres. Profound insight into threedimensional laminar mixing mechanisms is essential for better understanding of the behaviour of such systems and is in fact imperative for further advancement of (in particular, microscopic) mixing technology. This insight remains limited to date, however. The present study concentrates on a fundamental transport phenomenon relevant to laminar mixing: the formation and interaction of coherent structures in the web of three-dimensional paths of passive tracers due to fluid inertia. Such coherent structures geometrically determine the transport properties of the flow and thus their formation and topological structure are essential to three-dimensional mixing phenomena. The formation of coherent structures, its universal character and its impact upon three-dimensional transport properties is demonstrated by way of experimentally realizable time-periodic model flows. Key result is that fluid inertia induces partial disintegration of coherent structures of the non-inertial limit into chaotic regions and merger of surviving parts into intricate three-dimensional structures. This response to inertial perturbations, though exhibiting great diversity, follows a universal scenario and is therefore believed to reflect an essentially three dimensional route to chaos. Furthermore, a ﬿rst outlook towards experimental validation and investigation of the observed dynamics is made.
Original languageUndefined
Pages (from-to)5-34
Number of pages30
JournalJournal of fluid mechanics
Volume654
DOIs
Publication statusPublished - 2010

Keywords

  • EWI-19476
  • Low-Reynolds-numbers flows
  • Chaotic advection
  • METIS-276334
  • IR-75835
  • Nonlinear dynamical systems

Cite this

Pouransari, Z. ; Speetjens, M.F.M ; Clercx, H.J.H. / Formation of coherent structures by fluid inertia in three-dimensional laminar flows. In: Journal of fluid mechanics. 2010 ; Vol. 654. pp. 5-34.
@article{a04605820b744e40b4dee584040eef52,
title = "Formation of coherent structures by fluid inertia in three-dimensional laminar flows",
abstract = "Mixing under laminar flow conditions is key to a wide variety of industrial fluid systems of size extending from micrometres to metres. Profound insight into threedimensional laminar mixing mechanisms is essential for better understanding of the behaviour of such systems and is in fact imperative for further advancement of (in particular, microscopic) mixing technology. This insight remains limited to date, however. The present study concentrates on a fundamental transport phenomenon relevant to laminar mixing: the formation and interaction of coherent structures in the web of three-dimensional paths of passive tracers due to fluid inertia. Such coherent structures geometrically determine the transport properties of the flow and thus their formation and topological structure are essential to three-dimensional mixing phenomena. The formation of coherent structures, its universal character and its impact upon three-dimensional transport properties is demonstrated by way of experimentally realizable time-periodic model flows. Key result is that fluid inertia induces partial disintegration of coherent structures of the non-inertial limit into chaotic regions and merger of surviving parts into intricate three-dimensional structures. This response to inertial perturbations, though exhibiting great diversity, follows a universal scenario and is therefore believed to reflect an essentially three dimensional route to chaos. Furthermore, a ﬿rst outlook towards experimental validation and investigation of the observed dynamics is made.",
keywords = "EWI-19476, Low-Reynolds-numbers flows, Chaotic advection, METIS-276334, IR-75835, Nonlinear dynamical systems",
author = "Z. Pouransari and M.F.M Speetjens and H.J.H. Clercx",
note = "Z. Pouransari gratefully acknowledges {\"i}¬�nancial support from the Dutch Foundation for Fundamental Research on Matter (FOM)",
year = "2010",
doi = "10.1017/S0022112010001552",
language = "Undefined",
volume = "654",
pages = "5--34",
journal = "Journal of fluid mechanics",
issn = "0022-1120",
publisher = "Cambridge University Press",

}

Formation of coherent structures by fluid inertia in three-dimensional laminar flows. / Pouransari, Z.; Speetjens, M.F.M; Clercx, H.J.H.

In: Journal of fluid mechanics, Vol. 654, 2010, p. 5-34.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Formation of coherent structures by fluid inertia in three-dimensional laminar flows

AU - Pouransari, Z.

AU - Speetjens, M.F.M

AU - Clercx, H.J.H.

N1 - Z. Pouransari gratefully acknowledges �nancial support from the Dutch Foundation for Fundamental Research on Matter (FOM)

PY - 2010

Y1 - 2010

N2 - Mixing under laminar flow conditions is key to a wide variety of industrial fluid systems of size extending from micrometres to metres. Profound insight into threedimensional laminar mixing mechanisms is essential for better understanding of the behaviour of such systems and is in fact imperative for further advancement of (in particular, microscopic) mixing technology. This insight remains limited to date, however. The present study concentrates on a fundamental transport phenomenon relevant to laminar mixing: the formation and interaction of coherent structures in the web of three-dimensional paths of passive tracers due to fluid inertia. Such coherent structures geometrically determine the transport properties of the flow and thus their formation and topological structure are essential to three-dimensional mixing phenomena. The formation of coherent structures, its universal character and its impact upon three-dimensional transport properties is demonstrated by way of experimentally realizable time-periodic model flows. Key result is that fluid inertia induces partial disintegration of coherent structures of the non-inertial limit into chaotic regions and merger of surviving parts into intricate three-dimensional structures. This response to inertial perturbations, though exhibiting great diversity, follows a universal scenario and is therefore believed to reflect an essentially three dimensional route to chaos. Furthermore, a ﬿rst outlook towards experimental validation and investigation of the observed dynamics is made.

AB - Mixing under laminar flow conditions is key to a wide variety of industrial fluid systems of size extending from micrometres to metres. Profound insight into threedimensional laminar mixing mechanisms is essential for better understanding of the behaviour of such systems and is in fact imperative for further advancement of (in particular, microscopic) mixing technology. This insight remains limited to date, however. The present study concentrates on a fundamental transport phenomenon relevant to laminar mixing: the formation and interaction of coherent structures in the web of three-dimensional paths of passive tracers due to fluid inertia. Such coherent structures geometrically determine the transport properties of the flow and thus their formation and topological structure are essential to three-dimensional mixing phenomena. The formation of coherent structures, its universal character and its impact upon three-dimensional transport properties is demonstrated by way of experimentally realizable time-periodic model flows. Key result is that fluid inertia induces partial disintegration of coherent structures of the non-inertial limit into chaotic regions and merger of surviving parts into intricate three-dimensional structures. This response to inertial perturbations, though exhibiting great diversity, follows a universal scenario and is therefore believed to reflect an essentially three dimensional route to chaos. Furthermore, a ﬿rst outlook towards experimental validation and investigation of the observed dynamics is made.

KW - EWI-19476

KW - Low-Reynolds-numbers flows

KW - Chaotic advection

KW - METIS-276334

KW - IR-75835

KW - Nonlinear dynamical systems

U2 - 10.1017/S0022112010001552

DO - 10.1017/S0022112010001552

M3 - Article

VL - 654

SP - 5

EP - 34

JO - Journal of fluid mechanics

JF - Journal of fluid mechanics

SN - 0022-1120

ER -