Identifying coherent structures and vortex clusters in Taylor-Couette turbulence

Vamsi Spandan, Rodolfo Ostilla-Mónico, Detlef Lohse, Roberto Verzicco

Research output: Contribution to journalConference articleAcademicpeer-review

2 Citations (Scopus)
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Abstract

The nature of the underlying structures in Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders is investigated by two methods. First, the quadrant analysis technique for identifying structures with intense radial-azimuthal stresses (also referred to as 'Q's) of Lozano-Durán et al., (J. Fluid Mech. 694, 100-130) is used to identify the main structures responsible for the transport of angular velocity. Second, the vortex clusters are identified based on the analysis by del Álamo et al., (J. Fluid. Mech., 561, 329-358). In order to test these criteria, two different radius ratios η = ri/ro are considered, where ri and ro are the radii of inner and outer cylinder, respectively: (i) η = 0.5 and (ii) η = 0.909, which correspond to high and low curvature geometries, respectively and have different underlying structures. The Taylor rolls, i.e. the large-scale coherent structures, are effectively captured as 'Q's for the low curvature setup and it is observed that curvature plays a dominant role in influencing the size and volumes of these 'Q's. On the other hand, the vortex clusters are smaller in size when compared to the 'Q' structures. These vortex clusters are found to be taller in the case of η = 0.909, while the distribution of the lengths of these clusters is almost homogenous for both radius ratios.
Original languageEnglish
Article number012006
Number of pages13
JournalJournal of physics: Conference series
Volume708
DOIs
Publication statusPublished - 2016

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turbulence
vortices
curvature
radii
rotating cylinders
Couette flow
fluids
quadrants
angular velocity
geometry

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@article{21d8524a7f8e42228a255fcb6ff494c0,
title = "Identifying coherent structures and vortex clusters in Taylor-Couette turbulence",
abstract = "The nature of the underlying structures in Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders is investigated by two methods. First, the quadrant analysis technique for identifying structures with intense radial-azimuthal stresses (also referred to as 'Q's) of Lozano-Dur{\'a}n et al., (J. Fluid Mech. 694, 100-130) is used to identify the main structures responsible for the transport of angular velocity. Second, the vortex clusters are identified based on the analysis by del {\'A}lamo et al., (J. Fluid. Mech., 561, 329-358). In order to test these criteria, two different radius ratios η = ri/ro are considered, where ri and ro are the radii of inner and outer cylinder, respectively: (i) η = 0.5 and (ii) η = 0.909, which correspond to high and low curvature geometries, respectively and have different underlying structures. The Taylor rolls, i.e. the large-scale coherent structures, are effectively captured as 'Q's for the low curvature setup and it is observed that curvature plays a dominant role in influencing the size and volumes of these 'Q's. On the other hand, the vortex clusters are smaller in size when compared to the 'Q' structures. These vortex clusters are found to be taller in the case of η = 0.909, while the distribution of the lengths of these clusters is almost homogenous for both radius ratios.",
author = "Vamsi Spandan and Rodolfo Ostilla-M{\'o}nico and Detlef Lohse and Roberto Verzicco",
year = "2016",
doi = "10.1088/1742-6596/708/1/012006",
language = "English",
volume = "708",
journal = "Journal of physics: Conference series",
issn = "1742-6588",
publisher = "IOP Publishing Ltd.",

}

Identifying coherent structures and vortex clusters in Taylor-Couette turbulence. / Spandan, Vamsi; Ostilla-Mónico, Rodolfo; Lohse, Detlef; Verzicco, Roberto.

In: Journal of physics: Conference series, Vol. 708, 012006, 2016.

Research output: Contribution to journalConference articleAcademicpeer-review

TY - JOUR

T1 - Identifying coherent structures and vortex clusters in Taylor-Couette turbulence

AU - Spandan, Vamsi

AU - Ostilla-Mónico, Rodolfo

AU - Lohse, Detlef

AU - Verzicco, Roberto

PY - 2016

Y1 - 2016

N2 - The nature of the underlying structures in Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders is investigated by two methods. First, the quadrant analysis technique for identifying structures with intense radial-azimuthal stresses (also referred to as 'Q's) of Lozano-Durán et al., (J. Fluid Mech. 694, 100-130) is used to identify the main structures responsible for the transport of angular velocity. Second, the vortex clusters are identified based on the analysis by del Álamo et al., (J. Fluid. Mech., 561, 329-358). In order to test these criteria, two different radius ratios η = ri/ro are considered, where ri and ro are the radii of inner and outer cylinder, respectively: (i) η = 0.5 and (ii) η = 0.909, which correspond to high and low curvature geometries, respectively and have different underlying structures. The Taylor rolls, i.e. the large-scale coherent structures, are effectively captured as 'Q's for the low curvature setup and it is observed that curvature plays a dominant role in influencing the size and volumes of these 'Q's. On the other hand, the vortex clusters are smaller in size when compared to the 'Q' structures. These vortex clusters are found to be taller in the case of η = 0.909, while the distribution of the lengths of these clusters is almost homogenous for both radius ratios.

AB - The nature of the underlying structures in Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders is investigated by two methods. First, the quadrant analysis technique for identifying structures with intense radial-azimuthal stresses (also referred to as 'Q's) of Lozano-Durán et al., (J. Fluid Mech. 694, 100-130) is used to identify the main structures responsible for the transport of angular velocity. Second, the vortex clusters are identified based on the analysis by del Álamo et al., (J. Fluid. Mech., 561, 329-358). In order to test these criteria, two different radius ratios η = ri/ro are considered, where ri and ro are the radii of inner and outer cylinder, respectively: (i) η = 0.5 and (ii) η = 0.909, which correspond to high and low curvature geometries, respectively and have different underlying structures. The Taylor rolls, i.e. the large-scale coherent structures, are effectively captured as 'Q's for the low curvature setup and it is observed that curvature plays a dominant role in influencing the size and volumes of these 'Q's. On the other hand, the vortex clusters are smaller in size when compared to the 'Q' structures. These vortex clusters are found to be taller in the case of η = 0.909, while the distribution of the lengths of these clusters is almost homogenous for both radius ratios.

U2 - 10.1088/1742-6596/708/1/012006

DO - 10.1088/1742-6596/708/1/012006

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VL - 708

JO - Journal of physics: Conference series

JF - Journal of physics: Conference series

SN - 1742-6588

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