矩形微通道内液相黏度对气泡界面的作用机制  

Effect of liquid viscosity on bubble interface in the rectangular microchannel

作　　者：陈蔚阳 宋欣 殷亚然 张先明[1] 朱春英[2] 付涛涛[2] 马友光[2] CHEN Weiyang;SONG Xin;YIN Yaran;ZHANG Xianming;ZHU Chunying;FU Taotao;MA Youguang(School of Materials Science and Engineering,Zhejiang Sci-Tech University,National&Local Joint Engineering Research Center for Textile Fiber Materials and Processing Technology,Hangzhou 310018,Zhejiang,China;State Key Laboratory of Chemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]浙江理工大学材料科学与工程学院,纺织纤维材料与加工技术国家地方联合工程研究中心,浙江杭州310018 [2]化学工程联合国家重点实验室,天津大学化工学院,天津300072

出　　处：《化工进展》2023年第7期3468-3477,共10页Chemical Industry and Engineering Progress

基　　金：浙江省自然科学基金(LQ21B060009);国家自然科学基金(22008220);浙江省重点研发计划(2020C01143);浙江理工大学科研启动基金(19012403-Y)。

摘　　要：利用高速摄像机对矩形微通道中不同黏度体系下气泡的形状及界面演变进行实验研究。实验观察到子弹状、棒槌状、平尾状和尖尾状四种气泡形状,其中液弹的挤压力控制气泡尾部由凸形变平形或凹形,而受限空间效应和液相黏性剪切导致气泡形状为贴近壁面的尖尾状。基于两相Ca数和气液流率比绘制了气泡形状分布图并建立形状转变模型。平尾状和尖尾状气泡均是由棒槌状气泡演变而来,转变距离分别随气泡上游液弹压力和液相黏性剪切力的增加而减小,并且均与气/液流率比呈幂律关系,幂律指数小于零。尖尾状气泡破裂发生在尖端且存在临界条件,根据Ca数和气液流率比提出了破裂条件的良好预测模型。本工作对于矩形微通道内气泡的流动与破裂调控具有重要的指导意义。The morphology and interface evolution of bubbles with different liquid viscosities in a rectangular microchannel were investigated by a high-speed camera.Four bubble morphologies,bulletshaped,stick-shaped,flat-tailed and sharp-tailed,were observed.The evolution of bubble tail changed from convex to flat or concave,and to sharp near the wall were controlled respectively by the squeezing pressure of liquid slug and viscous shear under the confined space effect.Based on the two-phase Ca number and gas/liquid rate ratio,the bubble morphology distribution map was plotted and the shape transition model was established.Both the flat-tailed and sharp-tailed bubbles evolved from flat-tailed bubbles,and the transition distance decreased with the respective increase in liquid squeezing pressure and viscous shear,and showed a power-law relationship with the gas/liquid rate ratio with the negative exponent.The tips of sharp-tailed bubbles can break at the critical conditions,and a good model for predicting the breakup conditions was proposed with the Ca number and gas/liquid rate ratio.This work had important guidance for the regulation of the flow and breakup of bubbles in the rectangular microchannel.

关 键 词：微通道 黏度 气-液两相流 气泡 变形 破裂 

分 类 号：TQ021.1[化学工程]