Flow characterization of gas-liquid with different liquid properties in a Y-type microchannel using electrical resistance tomography and volume of fluid model

Abstract

BackgroundFlow characteristics in microscale reactors are one of the key factors in fast reaction systems, such as fine chemicals, pharmaceuticals, and nanopowders. In this work, the effects of liquid properties on the bubble flow characteristics in vertical circular microchannels are studied. MethodsUsing experiments (electrical resistance tomography and high-speed camera) and CFD simulation (volume of fluid method - continuous surface force) the effects of liquid phase properties on flow pattern transitions, liquid films, were investigated. Significant findingsThe average recognition rates of ERT in air - glycerol (µ = 0.885 mPa•s–1.912 mPa•s) and air - ethanol (σ = 38.7 mN/m - 72.0 mN/m) aqueous solution are over 84%. It was found that the liquid surface tension and liquid viscosity can change the internal shear force and interfacial force in the microchannel. When Ca > 0.0093, the bubbles and the inner wall of the microchannel form a liquid film. In addition, based on the experimental data, a modified equation for the gas holdup in the microchannel is proposed, which provides a reliable reference for the application of Y-type microchannels.