Study on the Characteristics in the Liquid Slug of Rising Slug Flow in Narrow Rectangular Channel

Gas-liquid slug flow is widely encountered in many practical industrial applications. A detailed understanding of the hydrodynamics of the liquid slug is of great importance in modeling the slug flow. A visualized study using a high speed video camera system was conducted to study liquid slug characteristics of slug flow in a vertical narrow rectangular channel (3.25×40mm²). It is found that three regions could be distinguished in the stable liquid slug tagging along the leading gas slug in most cases. The characteristics of a gas slug are greatly influenced by its position in the liquid slug, and the leading slug has a significant effect on the trailing slug in laminar or transition flow. The wake region of leading slug is also actually a sudden enlargement region where the water jet out of the liquid flim. The minimum stable liquid slug length L_min is obtained in the experiments ranging from 9 to 17D_h in fully developed turbulence flow.