Two-phase flow in vertical and inclined annuli Academic Article uri icon


  • This paper addresses the problem of estimating void fraction during upward cocurrent two-phase flow in annuli. To model the slip between the phases and the transition between the various regimes, the drift-flux approach is adapted. In analogy to flow behavior in circular conduits, four major flow regimes-bubbly, slug, churn and annular-are recognized. Expressions for void fraction in bubbly, slug and churn flow regimes are derived from the relationship between the phase velocities. The flowing mixture densities calculated from these expressions are useful for pressure gradient calculation. The annular flow regime was not investigated in the present work. The predictions of the proposed method for flow pattern transition and void fraction are compared with experimental data gathered for this work as well as from independent sources. Good agreement between experimental observations and the predictions is noted. 1992.

published proceedings

  • International Journal of Multiphase Flow

author list (cited authors)

  • Hasan, A. R., & Kabir, C. S.

citation count

  • 192

complete list of authors

  • Hasan, AR||Kabir, CS

publication date

  • January 1992