Transition of Bubbly to Slug Flow in a Short Vertical Channel of Gas-Liquid Two-Phase Flow

Transitions of bubbly to slug flow have been investigated for wide range of flow conditions via visualization technique. The effects of velocities of both phases were examined with variety of combinations and the experimentations were focused on the air-water flow with an industrial scale two-phase flow loop. The results show that the formations of slugs were easy with the increasing gas superficial velocity during a fixed liquid superficial velocity and were difficult when velocity of the liquid phase increases. These transitions were then evaluated using the ratio of velocities of both phases or called the slip ratio and from there a simple flow pattern map was constructed.