Buoyancy Profile Effects in Inclined Bubbly Shear Flow

  • Neale Thomas
  • K. Sanaullah
  • X. Yang
Part of the Fluid Mechanics and its Applications book series (FMIA, volume 36)

Summary

We describe some studies of nominally two-dimensional fully turbulent and developed duct flows (breadth/depth B/D-5; overall length/depth L/D 60; D-based Reynolds number Re>104) for inclination departures to 30 degrees from vertical at low voidages (<5% sectional average) representative of disperse regime using tap water bubbles (4mm) and smaller bubbles (2mm) stabilised in ionic solution. The bubbles were injected via a manifold located on the upper face at the entry station and turbulently dispersed transversely into the main body of flow. Pitot and static probe instrumentation, primitive but validated, provided adequate (10% local value) discrimination of main aspects of the mean velocity and voidage profiles at representative streamwise stations in L/D >30. Snapshot photography with axial slit-lighting was used to capture and characterise key features of buoyancy induced transverse layering and intermittent instability seen as Kelvin Helmoltz eddies responsible for sustaining dispersion at larger inclination departures of 10+ degrees.

Keywords

Mixed Convection Richardson Number Eddy Diffusion Vertical Flow Bubbly Flow 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Sanaullah, K. and Thomas, N.H. 1994. Velocity/voidage profiles for steeply inclined bubbly flows in "segregated-disperse" regime. ASME-FED 180, 119–128.Google Scholar
  2. Yang, X. and Thomas, N.H. 1993. Void fraction profiles in bubbly upward and downward flow. 6th Julich Workshop "Two-Phase Flow Predictions", 274–282.Google Scholar
  3. Yang, X. and Thomas, N.H. 1994. Simulation of particle and bubble dispersion in turbulent free shear flows. ASME-FED 185, 259–268.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Neale Thomas
    • 1
  • K. Sanaullah
    • 1
  • X. Yang
    • 1
  1. 1.FAST Team, School of Chemical EngineeringUniversity of BirminghamEngland

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