Pressure drop model of gas-liquid flow with mass transfer in tree-typed microchannels

In this study, a novel pressure drop model of gas-liquid flow with mass transfer in the tree-typed microchannels is proposed by extending from the gas-liquid flow with mass transfer in the single microchannel. For the gas-liquid flow with mass transfer in the single microchannel, the evolution of the length of the bubble along the microchannel is divided into the body shortening stage and the cap shrinking stage. At two different stages, the decreasing rates of the bubble length and velocity are obviously different. Consequently, a novel calculation method of the number of slug units based on the time scale is presented and the model of average pressure drop of a slug unit is revised. Then, compared with flow behavior in the single microchannel, two major flow patterns in the tree-typed microchannels are identified as non-breakup flow and breakup flow. In the non-breakup flow, bubbles alternately enter the last level channel, while in the breakup flow, bubbles rupture and daughter bubbles respectively enter the last level channel. Subsequently, the pressure drop model of the gas-liquid flow with mass transfer in the tree-typed microchannels is proposed by jointly considering the effects of the absorption and the bubble dynamics.