STRUCTURE OF AIR WATER BUBBLY FLOW IN A VERTICAL PIPE .2. VOID FRACTION, BUBBLE VELOCITY AND BUBBLE-SIZE DISTRIBUTION
STRUCTURE OF AIR WATER BUBBLY FLOW IN A VERTICAL PIPE .2. VOID FRACTION, BUBBLE VELOCITY AND BUBBLE-SIZE DISTRIBUTION
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DOI：
10.1016/s0017-9310(05)80290-x
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发表时间：
1993-03-01
影响因子：
5.2
通讯作者：
BANKOFF, SG
中科院分区：
文献类型：
--
作者：
LIU, TJ;BANKOFF, SG
在一篇配套论文（Liu and Bankoff. Int. J. Heat Mass Transfer 36, 1049-1060 (1993)）中，测量了一系列流动条件下空气-水气泡上升流中的液相速度和湍流特性。本文介绍了在相同条件下使用微型双传感器电阻率探头测量空隙率、气泡速度和气泡尺寸的径向分布。开发了一种基于液位和斜率阈值组合的新数字处理方法，用于电阻率探头的相位识别。局部平均气泡尺寸范围为 2 至 4 毫米。发现空隙率、气泡频率和气泡尺寸的分布在壁附近显示出明显的峰，在核心处变得平坦。总结和讨论了基于两个相空塔速度影响的实验结果和参数趋势。
In a companion paper (Liu and Bankoff. Int. J. Heat Mass Transfer 36, 1049-1060 (1993)) measurements were presented of liquid-phase velocity and turbulence properties in air-water bubbly upflow under a range of flow conditions. In this paper measurements of the radial profiles of void fraction, bubble velocity and bubbly size, using a miniature dual-sensor resistivity probe, under the same conditions are presented. A new digital processing method, based on threshold combinations of level and slope, was developed for phase identification by the resistivity probe. Local mean bubble sizes ranged from 2 to 4 mm. The profiles of void fraction, bubble frequency and bubble size are found to show distinct peaks near the wall, becoming flat at the core. Experimental findings and parametric trends based on the effects of superficial velocities of both phases are summarized and discussed.