垂直圆管内向上稀疏层流泡状流相分布的实验研究

采用三维照相法对垂直圆管内稀疏层流泡状流充分发展段的相分布进行了实验研究。得到了８个流动工况下均匀尺寸气泡形成的泡状流的空泡率分布以及６个流动工况下非均匀尺寸气泡形成的泡状流的总体和大、小气泡组各自的空泡率分布．实验结果表明当气泡组的平均直径小于约３．５ｍｍ时，其空泡率分布在管壁附近出现尖峰；当气泡组的平均直径大于约 ３．５ ｍｍ时，其空泡率分布的尖峰移向管中心；气泡尺寸对泡状流的相分布有重要影响．

PHASE DISTRIBUTION FOR UPWARD LAMINAR DILUTE BUBBLY FLOW WITH NON-UNIFORM BUBBLE SIZE IN A VERTICAL PIPE

A stereo-photography method was designed to determine the three-dimensional position and size of each bubble in flow field. Phase distributions in fully developed laminar bubbly flow were studied experimentally. The void fraction distributions for bubbly flows with approximately uniform bubble size have been measured under 8 different flow conditions and the void fraction distributions for bubbly flows with non-uniform bubble size have been measured under 6 different flow conditions. The results show that if the average bubble diameter of a group of bubbles is less than about 3.5 mm, the void fraction distribution will be wail-peaked both in uniform and non-uniform bubble flows. In non-uniform bubble flow, big bubbles with diameters over about 3.5 mm create the void fraction profile with a peak near the pipe center. Bubble size has great influence on phase distribution of bubbly flow.