VELOCITY CHARACTERISTICS OF LIQUID LUMPS AND ITS RELATION TO FLOW PATTERNS IN GAS-LIQUID TWO-PHASE FLOW IN VERTICAL CAPILLARY TUBES

摘要

The velocity characteristics of liquid lumps, such as a liquid slug, a disturbance wave and a base film wave were experimentally investigated to elucidate the flow phenomena of the vertical upward gas-liquid two-phase flow in capillary tubes. In this research we used tubes with six different diameters ranging from 6.0 to 0.5 mm. In order to make clear the importance of large liquid lumps in the flow in case that the large liquid lumps and many small waves co-exist, we proposed a momentum averaged mean velocity of liquid lumps. Based on the liquid lump velocity characteristics, a flow pattern map was reexamined by comparing with one for horizontal capillary tubes proposed by Kariyasaki et al. The correlations of two kinds of wave velocities which appeared in the annular flow region were also discussed.