Some hydrodynamic characteristics of bubbly mixtures flowing vertically upward in tubes

Abstract

An investigation of bubbly flow has been conducted in vertical plexiglass tubes using air and water at atmospheric pressure. The bubbly flow pattern is an entrance condition or a non-fully developed flow. A spontaneous changeover to slug or annular flow usually occurs if the channel is long enough. The experiments were performed in turbulent flow with superficial liquid velocities ranging from 5 to 30 ft/sec. The friction, hydrostatic, and momentum pressure drop have been separated and analyzed individually with the aid of two new experimental measurements. These measurements were of the wall shear force and the momentum flux. The validity of these measurements was verified with numerous single-phase tests. Several different air-water mixing methods, with the air always being introduced at the wall, had no affect on the results. Recommendations are presented for the use of these results when applied to steam-water mixtures.