Vertical two-phase flow part I. Flow pattern correlations

Two-phase gas-liquid flow has been investigated in a 1-inch internal diameter vertical tube coil containing two risers and a downcomer all connected by “U” bends. Flow pattern data were obtained in the three vertical tubes, each 17.30 ft. long, for five different air-liquid systems at about 25 psia over flow ranges of 0–700 lbm air/min-ft2 and 140–25300 lbm liquid/min-ft2. Liquid phase viscosities ranged from 1 to 12 cp. A flow pattern classification with six regimes including coring-bubble, bubbly-slug, falling film, falling bubbly-film, froth and annular flow regimes was established for downflow. Flow patterns in the bends were also classified. Data from the present investigation were used to formulate an empirical flow pattern graphical correlation for both upflow and downflow which is based upon the coordinates (Rv)1/2 and FrTP/A, where Rv is the delivered gas-to-liquid volume ratio, FrTP is the mixture Froude number, and A = μs/(SLσs3)1/4 in which μs, SL, σs are specific viscosity, specific density and specific surface tension respectively of the liquid with reference to water. The correlation was satisfactorily tested with independent literature data for upflow systems, including air-water, steam-water at various pressures, nitrogen-mercury and air-heptane, and data from flowing gas-oil wells. No independent literature data appear to be available for testing the correlation for downflow systems, but it is anticipated that the correlation will prove to be generally applicable. The coring phenomenon in downward bubble flow was examined by means of high speed motion photography and is explained by the development of a lift force on a bubble.

[1]  L. G. Neal.  LOCAL PARAMETERS IN COCURRENT MERCURY-NITROGEN FLOW , 1963 .

[2]  Donald S. Scott,et al.  Film inversion of cocurrent two‐phase flow in helical coils , 1967 .

[3]  R. Brown,et al.  THE CHEMISTRY OF ETHYLENE OXIDE: VI. THE ACID-CATALYZED REACTION OF ETHYLENE OXIDE WITH ETHANOL–WATER MIXTURES , 1960 .

[4]  N.C.J. Ros,et al.  Simultaneous Flow of Gas and Liquid As Encountered in Well Tubing , 1961 .

[5]  H. Tsien.  Symmetrical Joukowsky airfoils in shear flow , 1943 .

[6]  S. I. Rubinow,et al.  The transverse force on a spinning sphere moving in a viscous fluid , 1961, Journal of Fluid Mechanics.

[7]  S. Ostrach,et al.  Film instabilities in two‐phase flows , 1965 .

[8]  G. C. Gardner,et al.  Phase Distributions in Flow of an Air-Water Mixture round Bends and past Obstructions at the Wall of a 76-mm Bore Tube , 1969 .

[9]  G. W. Govier,et al.  The upward vertical flow of air‐water mixtures: II. Effect of tubing diameter on flow‐pattern, holdup and pressure drop , 1958 .

[10]  Graham B. Wallis,et al.  Two-Phase Slug Flow , 1961 .

[11]  W. R. Zahn,et al.  A Visual Study of Two-Phase Flow While Evaporating in Horizontal Tubes , 1964 .

[12]  Moissis.  THE TRANSITION FROM SLUG TO HOMOGENEOUS TWO-PHASE FLOWS. Topical Report No. 1. Report No. 304 , 1963 .

[13]  Neil C. Sher,et al.  Void fractions in two‐phase steam‐water flow , 1957 .

[14]  G. E. Smissaert.  TWO-COMPONENT TWO-PHASE FLOW PARAMETERS FOR LOW CIRCULATION RATES , 1963 .

[15]  Nick A. Radovcich,et al.  THE TRANSITION FROM TWO PHASE BUBBLE FLOW TO SLUG FLOW. Report No. 7-7673- 22. Technical Report No. 22 , 1962 .

[16]  P. Saffman,et al.  On the rise of small air bubbles in water , 1956, Journal of Fluid Mechanics.

[17]  G. W. Govier,et al.  The upward vertical flow of air‐water mixtures: III. Effect of gas phase density on flow pattern, holdup and pressure drop , 1960 .