The horizontal pipeline flow of air‐water mixtures

Abstract

AbstractA review and comparison of the various methods which have been proposed for the correlation of the pressure drop attending the flow of gas‐liquid mixtures is made. The friction factor and other terms employed in the correlations are related mathematically.The horizontal flow of air‐water mixtures has been investigated in a 41 ft. length of cellulose acetate butyrate tubing of 1.026 in. i. d. The average system pressure was held constant at 36 p.s.i.a. maintaining a constant air density of 0.18 lb./cu. ft. Flow pattern, holdup and pressure drop data were obtained at air‐water volume ratios from 0.1 to 200 (700 in some cases) for 10 superficial water velocities from 0.01 to 5.03 ft./sec. These data overlap and extend the range covered by previous investigators.The flow patterns observed at constant superficial water velocity with increasing air‐water ratio were: bubble, plug, stratified, wave or ripple, slug and film. Bubble, plug and slug flow were encountered only at superficial water velocities above about 0.1 ft./sec. while stratified flow was encountered only at superficial water velocities below about 1 ft./sec. and superficial air velocities below about 5 ft./sec.The holdup ratio, a measure of the relative accumulation of the water in the flow section, increased with air velocity for all superficial water velocities reaching a maximum value of over 50. At constant superficial air velocity the holdup ratio increased rapidly with decrease in superficial water velocity.The pressure drop data were converted to a friction factor based upon the density and the superficial velocity of the water. The friction factors were correlated with the superficial Reynolds number for the water, and the air‐water volume ratio. The data are compared in this form with previous data of Schneider, Thomsen, and Johnson and Abou‐Sabe.