竖直窄矩形通道内空气-水两相流中气弹运动速度研究

Study on Slug Velocity of Air-water Two-phase Flow in Vertical Narrow Rectangular Channel

以空气和水为工质，应用高速摄像仪，对竖直窄矩形通道（3．25mm×40ram）内气液两相弹状流进行了可视化实验研究。气、液相表观速度分别为0．1～2．51m／s和0．16～2．62m／s，工作压力为常压。实验中发现窄矩形通道内弹状流与圆管中存在较大差别，气弹多发生变形，高液相流速时变形更为严重。窄边液膜含气量较高，在高液相流速时窄边液膜不下落，宽边液膜中含有由气弹头部进人和气弹尾部进入的气泡。气弹速度受气弹头部形状和宽度影响较大，受气弹长度影响较小。气弹速度可由Ishii8LJones—Zuber模型计算，但在低液相折算速度时偏差较大，其主要原因为漂移速度计算值较实验值偏小。

Visualized investigation of the air-water two-phase slug flow in vertical narrow rectangular channel （3.25 mmX40 mm） was carried out with the help of a high speed video camera. The work pressure is atmospheric pressure and the superficial velocities of air and water cover 0.1-2.51 m/s and 0.16-2.62 m/s, respectively. The slug flow in narrow rectangular channel is found to be much different from that in circular pipe. Most of the slug bubbles are deformed, and much more seriously at high liquid velocity. The void fraction of narrow side liquid film is larger than that of wide side liquid film, and the film does not descend at high liquid velocity. It is observed that some tiny bubbles in the areas of the nose and tail of a slug bubble arc injected into the liquid film along the wide side. The nose shape of the slug bubble as well as its widthhas significant effect Ishii Jones-Zuber superficial velocity experimental values. on its velocity, whereas the effect of the length is very weak. The drift flux model can predict slug velocity well, except at low liquid by the reason of that the calculated drift velocity is less than