Abstract: In order to reduce or avoid the fluctuations from interface breakup, a meandering microchannel with curved multi-bends (44 turns) is fabricated, and investigations of scaling bubble/slug length in Taylor flow in a rectangular meandering microchannel are systematically conducted. Based on considerable experimental data, quantitative analyses for the influences of two important characteristic times, liquid phase physical properties and aspect ratio are made on the prediction criteria for the bubble/slug length of Taylor flow in a meandering microchannel. A simple principle is suggested to predict the bubble formation period by using the information of Rayleigh time and capillary time for six gas-liquid systems with average deviation of 10.96%. Considering physical properties of the liquid phase and cross-section configuration of the rectangular mcirochannel, revised scaling laws for bubble length are established by introducing Ca, We, Re and W/h whether for the squeezing-driven or shearing-driven of bubble break. In addition, a simple principle in terms of Garstecki-type model and bubble formation period is set-up to predict slug lengths. A total of 107 sets of experimental data are correlated with the meandering microchannel and operating range:0.001 < Ca_TP < 0.05, 0.06 < We_TP < 9.0, 18 < Re_TP < 460 using the bubble/slug length prediction equation from current work. The average deviation between the correlated data and the experimental data for bubble length and slug length is about 9.42% and 9.95%, respectively.

Key words: Meandering rectangular micro-channel, T-junction, Fluid properties, Bubble breakup mode, Bubble/slug length

摘要： In order to reduce or avoid the fluctuations from interface breakup, a meandering microchannel with curved multi-bends (44 turns) is fabricated, and investigations of scaling bubble/slug length in Taylor flow in a rectangular meandering microchannel are systematically conducted. Based on considerable experimental data, quantitative analyses for the influences of two important characteristic times, liquid phase physical properties and aspect ratio are made on the prediction criteria for the bubble/slug length of Taylor flow in a meandering microchannel. A simple principle is suggested to predict the bubble formation period by using the information of Rayleigh time and capillary time for six gas-liquid systems with average deviation of 10.96%. Considering physical properties of the liquid phase and cross-section configuration of the rectangular mcirochannel, revised scaling laws for bubble length are established by introducing Ca, We, Re and W/h whether for the squeezing-driven or shearing-driven of bubble break. In addition, a simple principle in terms of Garstecki-type model and bubble formation period is set-up to predict slug lengths. A total of 107 sets of experimental data are correlated with the meandering microchannel and operating range:0.001 < Ca_TP < 0.05, 0.06 < We_TP < 9.0, 18 < Re_TP < 460 using the bubble/slug length prediction equation from current work. The average deviation between the correlated data and the experimental data for bubble length and slug length is about 9.42% and 9.95%, respectively.

关键词: Meandering rectangular micro-channel, T-junction, Fluid properties, Bubble breakup mode, Bubble/slug length