Three-dimensionality in the wake of a rotating cylinder in a uniform flow

Anirudh Narayan Rao, Justin Scott Leontini, Mark Christopher Thompson, Kerry Hourigan

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The wake of a rotating circular cylinder in a free stream is investigated for Reynolds numbers Re= 400 and non-dimensional rotation rates of a = 2. 5. Two aspects are considered. The first is the transition from a steady flow to unsteady flow characterized by periodic vortex shedding. The two-dimensional computations show that the onset of unsteady flow is delayed to higher Reynolds numbers as the rotation rate is increased, and vortex shedding is suppressed for a = 2. 1 for all Reynolds numbers in the parameter space investigated. The second aspect investigated is the transition from two-dimensional to three-dimensional flow using linear stability analysis. It is shown that at low rotation rates of a = 1, the three-dimensional transition scenario is similar to that of the non-rotating cylinder. However, at higher rotation rates, the three-dimensional scenario becomes increasingly complex, with three new modes identified that bifurcate from the unsteady flow, and two modes that bifurcate from the steady flow. Curves of marginal stability for all of the modes are presented in a parameter space map, the defining characteristics for each mode presented, and the physical mechanisms of instability are discussed.
Original languageEnglish
Pages (from-to)1 - 29
Number of pages29
JournalJournal of Fluid Mechanics
Volume717
DOIs
Publication statusPublished - 2013

Cite this

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title = "Three-dimensionality in the wake of a rotating cylinder in a uniform flow",
abstract = "The wake of a rotating circular cylinder in a free stream is investigated for Reynolds numbers Re= 400 and non-dimensional rotation rates of a = 2. 5. Two aspects are considered. The first is the transition from a steady flow to unsteady flow characterized by periodic vortex shedding. The two-dimensional computations show that the onset of unsteady flow is delayed to higher Reynolds numbers as the rotation rate is increased, and vortex shedding is suppressed for a = 2. 1 for all Reynolds numbers in the parameter space investigated. The second aspect investigated is the transition from two-dimensional to three-dimensional flow using linear stability analysis. It is shown that at low rotation rates of a = 1, the three-dimensional transition scenario is similar to that of the non-rotating cylinder. However, at higher rotation rates, the three-dimensional scenario becomes increasingly complex, with three new modes identified that bifurcate from the unsteady flow, and two modes that bifurcate from the steady flow. Curves of marginal stability for all of the modes are presented in a parameter space map, the defining characteristics for each mode presented, and the physical mechanisms of instability are discussed.",
author = "Rao, {Anirudh Narayan} and Leontini, {Justin Scott} and Thompson, {Mark Christopher} and Kerry Hourigan",
year = "2013",
doi = "10.1017/jfm.2012.542",
language = "English",
volume = "717",
pages = "1 -- 29",
journal = "Journal of Fluid Mechanics",
issn = "0022-1120",
publisher = "Cambridge University Press",

}

Three-dimensionality in the wake of a rotating cylinder in a uniform flow. / Rao, Anirudh Narayan; Leontini, Justin Scott; Thompson, Mark Christopher; Hourigan, Kerry.

In: Journal of Fluid Mechanics, Vol. 717, 2013, p. 1 - 29.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Three-dimensionality in the wake of a rotating cylinder in a uniform flow

AU - Rao, Anirudh Narayan

AU - Leontini, Justin Scott

AU - Thompson, Mark Christopher

AU - Hourigan, Kerry

PY - 2013

Y1 - 2013

N2 - The wake of a rotating circular cylinder in a free stream is investigated for Reynolds numbers Re= 400 and non-dimensional rotation rates of a = 2. 5. Two aspects are considered. The first is the transition from a steady flow to unsteady flow characterized by periodic vortex shedding. The two-dimensional computations show that the onset of unsteady flow is delayed to higher Reynolds numbers as the rotation rate is increased, and vortex shedding is suppressed for a = 2. 1 for all Reynolds numbers in the parameter space investigated. The second aspect investigated is the transition from two-dimensional to three-dimensional flow using linear stability analysis. It is shown that at low rotation rates of a = 1, the three-dimensional transition scenario is similar to that of the non-rotating cylinder. However, at higher rotation rates, the three-dimensional scenario becomes increasingly complex, with three new modes identified that bifurcate from the unsteady flow, and two modes that bifurcate from the steady flow. Curves of marginal stability for all of the modes are presented in a parameter space map, the defining characteristics for each mode presented, and the physical mechanisms of instability are discussed.

AB - The wake of a rotating circular cylinder in a free stream is investigated for Reynolds numbers Re= 400 and non-dimensional rotation rates of a = 2. 5. Two aspects are considered. The first is the transition from a steady flow to unsteady flow characterized by periodic vortex shedding. The two-dimensional computations show that the onset of unsteady flow is delayed to higher Reynolds numbers as the rotation rate is increased, and vortex shedding is suppressed for a = 2. 1 for all Reynolds numbers in the parameter space investigated. The second aspect investigated is the transition from two-dimensional to three-dimensional flow using linear stability analysis. It is shown that at low rotation rates of a = 1, the three-dimensional transition scenario is similar to that of the non-rotating cylinder. However, at higher rotation rates, the three-dimensional scenario becomes increasingly complex, with three new modes identified that bifurcate from the unsteady flow, and two modes that bifurcate from the steady flow. Curves of marginal stability for all of the modes are presented in a parameter space map, the defining characteristics for each mode presented, and the physical mechanisms of instability are discussed.

UR - http://goo.gl/IUiq84

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DO - 10.1017/jfm.2012.542

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VL - 717

SP - 1

EP - 29

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

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