Liquid mean velocity and turbulence in a horizontal air-water bubbly flow

The liquid phase turbulent structure of an air-water bubbly horizontal flow in a circular pipe has been investigated experimentally. Three-dimensional measurements were implemented with two "X" type probes oriented in different planes, and local liquid-phase velocities and turbulent stresses were simultaneously obtained. Systematic measurements were conducted covering a range of local void fraction from 0 to 11.7%. The important experiment results and parametric trends are summarized and discussed.

颗粒击穿气泡时气泡的变形和破裂

通过高速摄像机拍摄研究了颗粒击穿半球气泡破碎的演变过程.观察并分析了气泡成型后边缘再生和对流情况、受到颗粒击穿时气泡破碎的概率、以及成孔后的气泡破碎行为.通过量纲分析以及实验研究发现,气泡破碎概率是雷诺数和韦伯数的函数,概率P=1.08(Re^(0.5)We^(0.25))^(0.664),且当Re^(0.5)We^(0.25)>1020时,概率升至100%,气泡破碎形成的不稳定性射流数量是奥内佐格数Oh的函数.气泡液膜的卷曲速度随溶液浓度提高而升高,气泡液厚度随浓度提高而减小.

水平管泡状流液相速度分布与相分布

用热膜探针测量了内径为 3 5mm的水平管泡状流中的液流速度 ,同时用双头电导探针测量了有关的相界面参数 ,结果表明 ,局部液流平均速度在靠管道下部的分布与单相液流的分布类似 ,在靠管道上部突然减小 ;局部液流平均速度在靠管道下部随气流折算速度的增加而增加 ,在靠管道上部则随气流折算速度的增加而减小 ;局部含气率和气泡频率随气流折算速度的增加而增大 ,在靠近管道上壁处有一峰值 。