Abstract: A high-speed camera was used to observe and record bubble breakup and distribution in bifurcating microchannels. Nitrogen and deionized water with 0.3% surfactant sodium dodecyl sulfate (SDS)-glycerol (20%, 40%,50%) were used as dispersed and continuous phases, respectively. Three different flow patterns were observed at the divergence: asymmetric breaking with permanent obstruction,asymmetric breaking with gap and non-breaking regimes. The transition between breakup and non-breakup was studied and compared with existing reports. The effects of flow rates of both phases and physical properties of fluids on the distributions of breaking bubbles were investigated. Both breakup lengths increased with increasing flow rate of gas phase and bubble length, and decreased with increasing liquid viscosity and flow rate. As the flow rate and viscosity of liquid phase increased, the degree of asymmetrical breakup decreased.

Key words: microchannels, bubble, breakup, distributions, Y-divergence

摘要： 利用高速摄像仪对气泡在非对称Y型微通道分岔口的破裂行为和分配规律进行了实验研究。采用氮气（N₂）作为分散相，含0.3%表面活性剂十二烷基硫酸钠（SDS）的蒸馏水-甘油（质量分数分别为20%、40%、50%）溶液为连续相。在分岔口处观察到了3种不同的气泡行为：无间隙的不对称破裂、有间隙的不对称破裂以及不破裂。考察了气泡破裂和不破裂行为之间的转变，并与文献进行了比较。考察了两相流率及物性对破裂气泡分配规律的影响。结果表明：破裂后两个子气泡的长度均随气相流量与气泡长度的增大而增大，随液相流量和黏度的增大而减小。随液相速度和黏度的增大，气泡破裂的不对称程度减弱。

关键词: 微通道, 气泡, 破裂, 分配, Y型分岔