SCALED ENTRAINMENT MEASUREMENTS IN RIPPLE-ANNULAR FLOW IN A SMALL TUBE

High pressure steam-water annular flow was simulated with scaled air-w ater and Freon-113 experiments. A unique Freon-113 loop was built to o btain low surface tension and high vapor density data on entrainment f raction. The results were compared with two correlations available in the open literature. The Ishii and Mishima correlation was capable to collapse the data for air-water, Freon-113 and steam-water experiments satisfactorily. However the correlation needs to be adjusted for high Weber numbers of the gas phase. The data was limited to the ripple-an nular regime because the film extraction technique is not reliable whe n the him becomes frothy. (C) 1998 Elsevier Science S.A. All rights re served.