VERTICAL 2-PHASE FLOW - PART II - EXPERIMENTAL SEMI-ANNULAR FLOW AND HOLD-UP

An experimental rig was constructed that enabled vertical co-current t wo-phase flow to be studied in a 0.026 m i.d. tube. For vertical air-w ater flow, pressure loss fluctuation characteristics were useful in he lping to identify phase patterns present and ensuring consistent opera tional conditions. Details are presented on the semi-annular flow regi me which formed between churn and annular flows. Liquid hold-up was me asured using the quick closing valve technique. Measurements showed th e liquid hold-up to be flow regime dependent in agreement with publish ed work. Prediction was achieved by the Nicklin(46) and Bonnecaze(19) relations for intermittent flow and the Spedding-Chen relation(17) for annular type flows.