完全阻塞气泡在T型不等宽微通道分岔口的破裂动力学  

Break-up dynamics of permanent obstructed bubble in T-junction with unequal width bifurcations

作　　者：温宇[1] 朱春英[1] 付涛涛[1] 马友光[1] 

机构地区：[1]天津大学化工学院,化学工程联合国家重点实验室,天津化学化工协同创新中心,天津300072

出　　处：《化工进展》2015年第11期3886-3891,共6页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21276175,21106093);天津市自然科学基金(13JCQNJC05500)项目

摘　　要：采用高速摄像仪对T型不等宽微通道分岔口的气泡完全阻塞破裂动力学行为进行了研究。实验以N2作为分散相,含0.5%十二烷基硫酸钠(SDS)的蒸馏水与甘油混合液作为连续相。结果表明:气泡完全阻塞破裂过程可以分为两个阶段:挤压阶段和快速夹断阶段。挤压阶段又可分为快速挤压阶段和慢速挤压阶段,快速挤压阶段尚未发现普遍的变化规律,慢速挤压阶段量纲为1气泡颈部最小宽度与时间存在指数关系:(1-wm/w0)∝t 0.62。表观流速和液相黏度的增加可使颈部变细速率加快,而气泡初始长度对气泡颈部变化的影响可以忽略。在快速夹断阶段,量纲为1气泡颈部最小宽度与剩余时间存在指数关系:wm/w0∝(T-t)0.32。A high speed camera was used to investigate the dynamics of permanent obstructed bubble break-up in a T-junction with unequal width bifurcations. N2 and distilled water-glycerol solution with 0.5% surfactant sodium dodecyl sulfate （SDS） were used as dispersed and continuous phases, respectively. The process of permanent obstructed bubble break-up could be divided into two stages：squeezing stage and pinch-off stage. The squeezing stage could further be partitioned into fast squeezing stage and slow squeezing stages. During the fast squeezing stage,the change of minimum width of bubble neck could not be generalized. During the slow squeezing stage,the change of dimensionless minimum width of bubble neck with time could be described by a power-law relationship：（1-wm/w0）∝t0.62. The thinning rate of bubble neck would be accelerated with the increase of superficial velocity and liquid viscosity,but was not affected by bubble length. During the pinch-off stage,the change of dimensionless minimum width of bubble neck with remaining time could be described by a power–law relationship：wm/w0∝（T-t）0.32.

关 键 词：微通道 气液两相流 气泡 破裂 界面 

分 类 号：TQ021.4[化学工程]