Formation characteristics of Taylor bubbles in a microchannel with a converging shape mixing junction

On the leakage flow around gas bubbles in slug flow in a microchannel

“…Another interesting phenomenon is that higher viscosity leads to both shorter start stage and linear moving stage in the squeezing stage, resulting in smaller bubbles. 40 The results here suggest that leakage flow is reduced when liquid is more viscous, as predicted by Wong et al 26 Net leakage flow at the T-junction and at the main channel Figure 10 shows the evolution of the net leakage flow as a function of liquid flow rate for different gas flow rates. The filled symbols represent the net leakage flow during bubble formation at the T-junction and the open symbols represent the net leakage flow for regular slug flow at the main channel.…”

An online method to measure mass transfer of slug flow in a microchannel

“…10. As can be seen, both gas bubbles and liquid slugs are shorter at higher concentrations of ethanol solutions due to their relatively high viscosity and low surface tension, which both lead to a faster generation of gas bubbles (Dang et al, 2013;Qian and Lawal, 2006). The generated gas bubbles also move faster when the ethanol concentration is higher.…”

“…Slug flow is considered as a promising flow pattern to improve reaction performance for many reasons: uniformly dispersed gas bubbles, fixed gas-liquid interface, narrow residence time distribution, enhanced mass or heat transfer due to inner recirculation of liquid slugs and flexible operating conditions. Up to now, wide attention has been paid to slug flow on various aspects such as bubble formation process and bubble length (Dang et al, 2013;Garstecki et al, 2006;van Steijn et al, 2007), bubble shape and liquid film distribution in the cross section (Fries et al, 2008b;Han and Shikazono, 2009;Kreutzer et al, 2005a;Thulasidas et al, 1995), gas hold-up or void fraction (Kawahara et al, 2005;Xiong and Chung, 2007), pressure drop (Kreutzer et al, 2005a,b;Yue et al, 2009) and so on. Even for some major drawbacks that hinder the large scale application of microreactors such as distribution of multichannels (Al-Rawashdeh et al, 2012) and short residence time/reaction time , significant progress has been made.…”

Numerical study of Taylor bubbles rising in a stagnant liquid using a level-set/moving-mesh method

“…Since the publications of the original works of Davies and Taylor [25] and White and Beardmore [26], several approaches have been assessed to simulate Taylor bubbles. Rigorous experimental research have been reported [27,28,29,30], theoretical models have been proved [31,32] and numerical methods have been addressed, by using Volume of Fluid method [33], Front Tracking method [34], Lattice Bolzmann method [35,36], and others [37,38]. To the authors' knowledge, the present work is the first approach to the Taylor bubble problem by means of a Conservative Level Set method.…”