摘要
以氮气和水为实验介质,利用高速摄像机对水力直径为1.15 mm的矩形小通道内的气液两相垂直向上流动特性进行可视化研究,依次得到泡状流、弹状流、搅拌流和环状流4种典型的流型图像。针对小通道内气泡之间相互无遮掩性的优势,运用图像处理技术对流型图像分形增强,检测气泡边缘并填充后根据提出的气相体积模型,得到两相流动的含气率。结合实验数据,根据分液相Reynolds数把流动分为层流区、过渡区和紊流区,并对Chisholm关系式进行修正,结果表明:修正后的压降模型能较好地预测本文实验结果。
Based on high speed camera,nitrogen-water two-phase vertical upward flow characteristics was studied in a small rectangular channel with hydraulic diameter of 1.15 mm.Four typical flow pattern images（bubbly flow,slug flow,churn flow and annular flow） were observed.According to non-overlapping characteristics among bubbles in the small rectangular channel,four typical flow patterns images were enhanced by using digital image processing techniques.After detecting bubble＇s edge and filling fully,gas void fraction was obtained by the proposed models.Two-phase flow was distinguished by the liquid Reynolds number as laminar region,transition region and turbulent region,and a modified Chisholm equation was proposed,The results showed that the modified Chisholm correlation equation could better predict pressure drop in this study.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2011年第5期1226-1232,共7页
CIESC Journal
基金
吉林省科技发展项目(20060704)~~
关键词
气液两相流
小通道
图像处理
含气率
压降
gas-liquid two-phase flow
small channel
image processing
void fraction
pressure drop
