Experimental investigations and modelling on the transition from bubble to slug flow in vertical pipes


Experimental investigations and modelling on the transition from bubble to slug flow in vertical pipes

Lucas, D.; Krepper, E.; Prasser, H.-M.

To qualify CFD codes for two-phase flows, they have to be equipped with constitutive laws describing the interaction between the gaseous and the liquid phases. In the case of bubble flow this particularly concerns the forces acting on the bubbles and bubble coalescence and break-up. To obtain detailed experimental data, an electrode wire-mesh sensor was used, which enables the measurement of the phase distribution with a very high resolution in space and in time. Air-water flow at ambient conditions in a vertical pipe (51.2 mm inner diameter) is investigated to have well defined boundary conditions. Local bubble size distributions are calculated from the data. The measurements were done in different distances from the gas injection device. As a result the development of bubble size distributions as well as the development of the radial gas fraction profiles can be studied. It was found, that the bubble size distribution as well as local effects determine the transition from bubble flow to slug flow. The data are used for the development of a model, which predicts the development of the bubble size distribution and the transition from bubble flow to slug flow in case of stationary flow in a vertical pipe.

Keywords: Two-phase flow; Flow pattern; Bubble Flow; Slug Flow

  • Lecture (Conference)
    Proceedings of the German-Japanese Workshop on Multiphase Flow, Karlsruhe, August 25-27, 2002, FZKA 6759(http://www.emsi.fzk.de/gjwmf2002/pdf/Proceedings_FZKA6759.pdf), pp. C-1 - C-12
  • Contribution to proceedings
    Proceedings of the German-Japanese Workshop on Multiphase Flow, Karlsruhe, August 25-27, 2002, FZKA 6759(http://www.emsi.fzk.de/gjwmf2002/pdf/Proceedings_FZKA6759.pdf), pp. C-1 - C-12

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Publ.-Id: 4589