Investigation of Bubble Breakup in Laminar, Transient, and Turbulent Regime Behind Micronozzles

Gas-liquid flow in microchannels has drawn much attention in the last years in research fields of analytics and applications such as oxidations or hydrogenations. High interfacial area leads to increased mass transfer and intensified reactions. Since surface forces are increasingly important on small scale, bubble coalescence is detrimental and leads to Taylor bubble flow in microchannels. To overcome this limitation, we have investigated the gas-liquid flow through nozzles and particularly the bubble breakup behind the nozzle. Two different regimes of bubble breakup were identified, laminar and turbulent with different mechanisms. Although turbulent breakup is not common in microchannels, its mechanisms were studied for the first time and can give new insight for two-phase flow mechanisms.