Energy contents and vortex dynamics in Mode-C transition of wired-cylinder wake

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Abstract

The 3D transition of the ¿ow behind a circular cylinder with a near-wake wire disturbance has been investigated experimentally. The ¿ow is oriented horizontally and the wire is positioned in the upper half of the wake. We performed ¿ow visualization and particle image velocimetry experiments to investigate the in¿uence of the wire on various properties of the ¿ow, such as the dynamics of the spanwise structures. Experiments were performed in the Reynolds number range of Re = 165–300. It is shown that in Mode-C transition of the wired cylinder wake, some part of the streamwise vorticity content of the upper von Karman vortices located at the perturbed side, is transferred to the secondary vortices. This vorticity transfer results in upper von Karman vortices which are weaker than the lower ones. The analysis of the discrete energy content of the wake supports this analysis by showing that the energy intensity at von Karman vortex shedding frequency f0 at the perturbed side of the wake is less than the energy intensity in the lower half. This leads to conclusion that the excess energy is transferred to the subharmonic frequency f1˜ f0/2.
Original languageEnglish
Article number054103
Pages (from-to)054103-1/18
JournalPhysics of Fluids
Volume25
Issue number5
DOIs
Publication statusPublished - 2013

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wakes
Vortex flow
vortices
wire
vorticity
Wire
Vorticity
near wakes
vortex shedding
energy
circular cylinders
particle image velocimetry
Vortex shedding
Reynolds number
Circular cylinders
disturbances
Velocity measurement
Visualization
Experiments

Cite this

@article{ec8342832c83441089c29f3301c8ec04,
title = "Energy contents and vortex dynamics in Mode-C transition of wired-cylinder wake",
abstract = "The 3D transition of the ¿ow behind a circular cylinder with a near-wake wire disturbance has been investigated experimentally. The ¿ow is oriented horizontally and the wire is positioned in the upper half of the wake. We performed ¿ow visualization and particle image velocimetry experiments to investigate the in¿uence of the wire on various properties of the ¿ow, such as the dynamics of the spanwise structures. Experiments were performed in the Reynolds number range of Re = 165–300. It is shown that in Mode-C transition of the wired cylinder wake, some part of the streamwise vorticity content of the upper von Karman vortices located at the perturbed side, is transferred to the secondary vortices. This vorticity transfer results in upper von Karman vortices which are weaker than the lower ones. The analysis of the discrete energy content of the wake supports this analysis by showing that the energy intensity at von Karman vortex shedding frequency f0 at the perturbed side of the wake is less than the energy intensity in the lower half. This leads to conclusion that the excess energy is transferred to the subharmonic frequency f1˜ f0/2.",
author = "I. Yildirim and C.C.M. Rindt and {Steenhoven, van}, A.A.",
year = "2013",
doi = "10.1063/1.4801849",
language = "English",
volume = "25",
pages = "054103--1/18",
journal = "Physics of Fluids",
issn = "1070-6631",
publisher = "American Institute of Physics",
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}

Energy contents and vortex dynamics in Mode-C transition of wired-cylinder wake. / Yildirim, I.; Rindt, C.C.M.; Steenhoven, van, A.A.

In: Physics of Fluids, Vol. 25, No. 5, 054103, 2013, p. 054103-1/18.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Energy contents and vortex dynamics in Mode-C transition of wired-cylinder wake

AU - Yildirim, I.

AU - Rindt, C.C.M.

AU - Steenhoven, van, A.A.

PY - 2013

Y1 - 2013

N2 - The 3D transition of the ¿ow behind a circular cylinder with a near-wake wire disturbance has been investigated experimentally. The ¿ow is oriented horizontally and the wire is positioned in the upper half of the wake. We performed ¿ow visualization and particle image velocimetry experiments to investigate the in¿uence of the wire on various properties of the ¿ow, such as the dynamics of the spanwise structures. Experiments were performed in the Reynolds number range of Re = 165–300. It is shown that in Mode-C transition of the wired cylinder wake, some part of the streamwise vorticity content of the upper von Karman vortices located at the perturbed side, is transferred to the secondary vortices. This vorticity transfer results in upper von Karman vortices which are weaker than the lower ones. The analysis of the discrete energy content of the wake supports this analysis by showing that the energy intensity at von Karman vortex shedding frequency f0 at the perturbed side of the wake is less than the energy intensity in the lower half. This leads to conclusion that the excess energy is transferred to the subharmonic frequency f1˜ f0/2.

AB - The 3D transition of the ¿ow behind a circular cylinder with a near-wake wire disturbance has been investigated experimentally. The ¿ow is oriented horizontally and the wire is positioned in the upper half of the wake. We performed ¿ow visualization and particle image velocimetry experiments to investigate the in¿uence of the wire on various properties of the ¿ow, such as the dynamics of the spanwise structures. Experiments were performed in the Reynolds number range of Re = 165–300. It is shown that in Mode-C transition of the wired cylinder wake, some part of the streamwise vorticity content of the upper von Karman vortices located at the perturbed side, is transferred to the secondary vortices. This vorticity transfer results in upper von Karman vortices which are weaker than the lower ones. The analysis of the discrete energy content of the wake supports this analysis by showing that the energy intensity at von Karman vortex shedding frequency f0 at the perturbed side of the wake is less than the energy intensity in the lower half. This leads to conclusion that the excess energy is transferred to the subharmonic frequency f1˜ f0/2.

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DO - 10.1063/1.4801849

M3 - Article

VL - 25

SP - 054103-1/18

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 5

M1 - 054103

ER -