Controlling effects in countercurrent two-phase flow

In many two-phase-flow situations, the prediction of conditions likely to instigate the change in flow regime from stratified to slug is important because this change or ''choking'' of a pipe may dictate the maximum flow rates possible in that pipe. This paper considers the appropriate parameters in the development of a suitable stability criterion for this transition in countercurrent flow. This criterion is then quantified with the results from an experimental test rig. Finally, a typical two-phase petrochemical situation is examined by use of this stability criterion, and the produced results are compared with previous stratified-flow predictions to identify the controlling effect.