Acta Mechanica Sinica

, Volume 20, Issue 3, pp 206–211 | Cite as

Two-phase flow patterns in a 90° bend at microgravity

  • Zhao Jianfu
  • K. S. Gabriel


Bends are widely used in pipelines carrying single-and two-phase fluids in both ground and space applications. In particular, they play more important role in space applications due to the extreme spatial constraints. In the present study, a set of experimental data of two-phase flow patterns and their transitions in a 90° bend with inner diameter of 12.7 mm and curvature radius of 76.5 mm at microgravity conditions are reported. Gas and liquid superficial velocities are found to range from (1.0≈23.6) m/s for gas and (0.09≈0.5) m/s for liquid, respectively. Three major flow patterns, namely slug, slug-annular transitional, and annular flows, are observed in this study. Focusing on the differences between flow patterns in bends and their counterparts in straight pipes, detailed analyses of their characteristics are made. The transitions between adjoining flow patterns are found to be more or less the same as those in straight pipes, and can be predicted using Weber number models satisfactorily. The reasons for such agreement are carefully examined.

Key Words

two-phase flow flow patterns 90° bend microgravity 


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Copyright information

© Chinese Society of Theoretical and Applied Mechanics 2004

Authors and Affiliations

  • Zhao Jianfu
    • 1
  • K. S. Gabriel
    • 2
  1. 1.National Microgravity Laboratory, Institute of MechanicsChinese Academy of SciencesBeijingChina
  2. 2.Microgravity Research Group, College of EngineeringUniversity of SaskatchewanSaskatoonCanada

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