竖直窄矩形通道内弹状流中液膜特性研究

气液两相弹状流广泛存在于工程领域，弹状流中液膜特性对弹状流模型的建立具有重要意义。为此利用高速摄像系统，对竖直窄矩形通道(3.25 mm×40 mm)内弹状流中液膜进行了可视化研究。实验中发现窄矩形通道中气弹左右两侧窄边液膜厚度不等且存在波动，但其对两侧液膜速度影响较小，两侧液膜速度相等。液膜脱离厚度主要受两相流速及气弹长度影响。液膜脱离速度随液相折算速度增加而增大；在低液相流速时，随气相折算速度增加而减小；当液相流速≥1.204 m/s时，液膜不下落，液膜脱离速度随气相速度变化较小，主要受液相流速影响。

Study on Liquid Film Characteristics of Slug Flow in Vertical Narrow Rectangular Channel

Gas-liquid slug flow is widely encountered in many practical industrial applications. A detailed understanding of the hydrodynamics of the liquid film surrounding gas slug has important significance for modeling of the slug flow. Non-intrusive flow visualization using a high speed video camera system was applied to study liquid film characteristics of slug flow in a vertical narrow rectangular channel (3.25 mm×40 mm). The liquid film thicknesses on both left and right narrow sides surrounding gas slug are different and wavy, but it has a weak effect on liquid film velocity and the velocities on two sides are equal. The gas and liquid velocity as well as the length of gas slug have a significant effect on the liquid film breaking away thickness. The liquid film breaking away velocity increases with liquid superficial velocity, and decreases with the increase of gas superficial velocity at low liquid velocity. The film does not descend and the gas superficial velocity has no significant effect on liquid film breaking away velocity at high liquid velocity (j_L≥1.204 m/s), it is mainly determined by the liquid flow rate.