VERTICAL 2-PHASE FLOW - PART I - FLOW REGIMES

For vertical air-water flow, five flow regimes were identified by a co mbination of visual/ video techniques and pressure loss fluctuation ch aracteristics in an 0.026 m i.d. tube. Checks against existing how reg ime maps indicated that it was unlikely that a universal map will be d erived that will correctly predict phase regimes in vertical flow. Exi sting theoretical transition equations were shown to have difficulty i n handling the effect of diameter on the slug to churn transition. The churn to annular transition proved hard to predict at higher liquid r ates. Two new relations are presented that predicted the transitions f or the slug to churn and churn to annular regimes.