### Abstract

The onset and nonlinear dynamics of swirling flows in relatively tall cylinders driven by the rotation of an endwall are studied numerically. These flows are distinguished from the more widely studied swirling flows in shorter cylinders; the instability in the taller cylinders is direct to three-dimensional flows rather than to unsteady axisymmetric flows. The simulations are in very good agreement with recent experiments in terms of the critical Reynolds number, frequency, and azimuthal wavenumber of the flows, but there is disagreement in the interpretation of these flows. We show that these flows are indeed rotating waves and that they have the same vorticity distributions as the flows measured using particle image velocimetry in the experiments. Identifying these as rotating waves gives a direct connection with prior linear stability analysis and the three-dimensional flows found in shorter cylinders as secondary instabilities leading to modulated rotating waves.

Original language | English (US) |
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Article number | 014101 |

Journal | Physics of Fluids |

Volume | 24 |

Issue number | 1 |

DOIs | |

State | Published - Jan 5 2012 |

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### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

**Three-dimensional swirling flows in a tall cylinder driven by a rotating endwall.** / Lopez, Juan.

Research output: Contribution to journal › Article

*Physics of Fluids*, vol. 24, no. 1, 014101. https://doi.org/10.1063/1.3673608

}

TY - JOUR

T1 - Three-dimensional swirling flows in a tall cylinder driven by a rotating endwall

AU - Lopez, Juan

PY - 2012/1/5

Y1 - 2012/1/5

N2 - The onset and nonlinear dynamics of swirling flows in relatively tall cylinders driven by the rotation of an endwall are studied numerically. These flows are distinguished from the more widely studied swirling flows in shorter cylinders; the instability in the taller cylinders is direct to three-dimensional flows rather than to unsteady axisymmetric flows. The simulations are in very good agreement with recent experiments in terms of the critical Reynolds number, frequency, and azimuthal wavenumber of the flows, but there is disagreement in the interpretation of these flows. We show that these flows are indeed rotating waves and that they have the same vorticity distributions as the flows measured using particle image velocimetry in the experiments. Identifying these as rotating waves gives a direct connection with prior linear stability analysis and the three-dimensional flows found in shorter cylinders as secondary instabilities leading to modulated rotating waves.

AB - The onset and nonlinear dynamics of swirling flows in relatively tall cylinders driven by the rotation of an endwall are studied numerically. These flows are distinguished from the more widely studied swirling flows in shorter cylinders; the instability in the taller cylinders is direct to three-dimensional flows rather than to unsteady axisymmetric flows. The simulations are in very good agreement with recent experiments in terms of the critical Reynolds number, frequency, and azimuthal wavenumber of the flows, but there is disagreement in the interpretation of these flows. We show that these flows are indeed rotating waves and that they have the same vorticity distributions as the flows measured using particle image velocimetry in the experiments. Identifying these as rotating waves gives a direct connection with prior linear stability analysis and the three-dimensional flows found in shorter cylinders as secondary instabilities leading to modulated rotating waves.

UR - http://www.scopus.com/inward/record.url?scp=84856427297&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84856427297&partnerID=8YFLogxK

U2 - 10.1063/1.3673608

DO - 10.1063/1.3673608

M3 - Article

AN - SCOPUS:84856427297

VL - 24

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 1

M1 - 014101

ER -