Transition to oscillatory natural convection of cold water in a vertical annulus

C. J. Ho, F. J. Tu

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10 Citations (Scopus)

Abstract

In the present study laminar transition to oscillatory convection of cold water in a vertical annulus of aspect ratio 8 and radius ratio 2 is investigated by direct numerical simulations for two values of density inversion parameter, θm = 0.4 and 0.5. The vertical walls of the annulus are maintained at constant but different temperatures, while the horizontal walls are assumed adiabatic. Numerical results manifest that the buoyancy-driven flow in the annulus experiences a Hopf bifurcation into a periodic oscillation regime at the critical Rayleigh numbers, which are dependent on the density inversion parameter. The critical Rayleigh number for θm = 0.4 is found to be more than two times of that corresponding to θm = 0.5. Nature of the transition has also been identified by examining the contributions made by the flow shear and/or the buoyancy force to the generation of fluctuating kinetic energy for the self-sustained oscillatory convection in the annulus.

Original languageEnglish
Pages (from-to)1559-1572
Number of pages14
JournalInternational Journal of Heat and Mass Transfer
Volume41
Issue number11
DOIs
Publication statusPublished - 1998 Jun

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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