Vortex Breakdown Phenomena in a Circular Pipe (5th Report, Axisymmetric Breakdown in Rotating Conical Pipes)

Yoshikazu Suematsu, Tadaya Ito, Toshiyuki Hayase

Research output: Contribution to journalArticlepeer-review

Abstract

It is known that a swirling flow in a diverging pipe breaks down more easily than a flow in a converging one. In this report, experiments are made using diverging, converging and straight pipes, in order to clarify the relation between the shape of pipes and the occurrence of the breakdown. Swirling flow fields, that are realized by rotation of pipes, are measured by a Laser-Doppler-Velocimeter. When each pipe rotates faster than a certain critical value, a stationary internal wave occurs. The vortex breakdown phenomenon is due to the internal waves in swirling flows, as pointed out in preceding reports. In the diverging pipe, the amplitude of the wave is rather smaller than that in the converging pipe; but the mean axial flow near the axis is fairly retarded, so that the flow reverses at the trough of the superposed wave component, and bubble type breakdown appears. A mathematical model is also presented to give a qualitative explanation of the effect of a sectional area variation.

Original languageEnglish
Pages (from-to)1626-1635
Number of pages10
JournalTransactions of the Japan Society of Mechanical Engineers Series B
Volume52
Issue number476
DOIs
Publication statusPublished - 1986
Externally publishedYes

Keywords

  • Conical Pipe Rotating Pipe
  • Flow Measurement
  • Fluid Vibration
  • Inertial Wave
  • Vortex Breakdown

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering

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