Experimental and numerical results on three-dimensional instabilities in a rotating disk-tall cylinder flow

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Abstract

The three-dimensional axisymmetry-breaking instability of axisymmetric flow between a rotating lid and a stationary cylinder is analyzed both numerically and experimentally for the case of tall cylinders with the height/radius aspect ratio between 3.3 and 5.5. A complete stability diagram for the primary three-dimensional instability is obtained experimentally and computed numerically. The instability sets in due to different three-dimensional disturbance modes that are characterized by different azimuthal wavenumbers. The critical Reynolds numbers and associated frequencies are identified for each mode. The onset of three-dimensional flow behavior is measured by combining the high spatial resolution of particle image velocimetry and the temporal accuracy of laser Doppler anemometry. The results are compared to the numerical stability analysis. The measured onset of three dimensionality is in a good agreement with the numerical results. Disagreements observed in supercritical regimes can be explained by secondary bifurcations that are not accounted for by linear stability analysis of the primary base flow. ©2009 American Institute of Physics
Original languageEnglish
JournalPhysics of Fluids
Volume21
Issue number5
Pages (from-to)054102
ISSN1070-6631
DOIs
Publication statusPublished - 2009

Bibliographical note

Copyright (2009) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Keywords

  • flow visualisation
  • rotational flow
  • flow instability
  • confined flow
  • bifurcation
  • laser Doppler anemometry

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