Dimensionless Analyses of Liquid–Liquid–Liquid Three-Phase Flow Patterns in a Confined Microchannel

Tao, Chun; Zhang, Taoxian; Ge, Shixiong; Huang, W.D.; Wang, Wei; Pan, Dawei; Chu, Liang‐Yin

doi:10.1021/acs.iecr.3c01415

Cited by 3 publications

(1 citation statement)

References 43 publications

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“…The volume of fluid-continuum surface force (VOF-CSF) model has been developed to capture the interface motions with good mass conservation property, − in which the construction of phase interfaces is realized by calculating the volume fraction of phases in the control volume, and the sum of the volume fractions of all phases in each control volume is equal to 1. If the volume fraction of q th fluid in the cell is denoted as α q , the α q = 0 means that the cell is empty without q th fluid; α q = 1 means that the cell is filled with all q th fluids; while 0 < α q < 1 means that the cell contains q th fluid interface between the cell and one or more other fluids.…”

Section: Methodsmentioning

confidence: 99%

Effects of Rheological Properties of Non-Newtonian Middle Fluids on the Formation Dynamics of Double Emulsions in Coflowing Microfluidic Emulsification

Jiao,

Zhang,

Wang

et al. 2024

Ind. Eng. Chem. Res.

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Effects of the rheological properties of non-Newtonian middle fluids on the formation dynamics of double emulsions in coflowing microfluidic emulsification are systematically ascertained by both experimental investigation and numerical simulation with a volume of fluid-continuum surface force model. In the experiments, with non-Newtonian fluids as the middle fluids for the generation of double emulsions, six various flow regimes, including dripping, jetting, transition, nonbreakup, parallel, and multicore regimes, are distinguished, and the corresponding formation mechanisms of such distinct flow regimes are further comprehensively revealed by analyzing the flow field structures and viscosity distributions inside the double emulsions. Particularly, a large flow velocity of the outer fluid only contributes to the generation of a transition regime but not a jetting regime because of the shear-thinning property of the non-Newtonian middle fluid. The regimes in the flow pattern diagrams dependent on the capillary number of the outer fluid, the Weisenberg number of the middle fluid, and the Reynolds number of the inner fluid are obtained. Besides, the size variation laws of double emulsions under various operation conditions are also illustrated. As the flow velocity of the middle fluid increases, the inner diameter of the resultant double emulsions remains constant within a specific range because the increase of the flow velocity always results in the decrease of the middle fluid viscosity, thus determining the nearly invariant viscous shearing force acting on the inner fluid. Finally, the prediction correlations for the dimensionless inner and outer diameters of double emulsions with several key dimensionless numbers are established, and the prediction errors are within ±10%. The results of this study provide valuable guidance for the preparation of monodisperse double emulsions with non-Newtonian fluids as the middle fluids in a controllable and precise manner.

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Section: Methodsmentioning

confidence: 99%

Effects of Rheological Properties of Non-Newtonian Middle Fluids on the Formation Dynamics of Double Emulsions in Coflowing Microfluidic Emulsification

Jiao,

Zhang,

Wang

et al. 2024

Ind. Eng. Chem. Res.

Self Cite

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Numerical study of double emulsion generation in a flow-focusing microchannel by multiple-relaxation-time lattice Boltzmann method

Wang,

et al. 2024

Physics of Fluids

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Microfluidic technology applied for the controlled production of double emulsions has gained significant interest in biomedicine and material synthesis. The precise regulation of emulsion size depends on the in-depth study of the formation mechanism. A ternary multiple-relaxation-time lattice Boltzmann model with robust stability and multiphase accuracy is established and applied to investigate the formation mechanism of double emulsions within a flow-focusing microchannel. Integrated with the regularized and convective boundary conditions, the present model proves adept at simulating the complex multiphase flow behavior in microchannels under various properties and operation parameters. Extensive validations involving static and dynamic cases demonstrate the model accuracy in capturing three-phase interactions and multiphase flow fields while also significantly enhancing stability and accommodating a broader range of viscosity ratios. Our systematic investigation involves the influence of flow rate, viscosity ratio, interfacial tension ratio, and orifice section size on the formation of double emulsions. The results show the impact of flow rate on flow patterns and inner phase volume, revealing an expanded operation range of the dripping pattern brought by the increased outer phase flow rate. Notably, two distinct droplet formation mechanisms, i.e., shear mode and squeeze mode, are identified across a wide range of viscosity ratios. Additionally, the investigation of interfacial tension ratios focuses on assessing the effect of various interfacial tension combinations, while alterations in orifice width reveal its significant impact on shear strength and dispersed phase dynamics. This work deepens the understanding of double emulsion mechanics and offers a versatile platform for future research.

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Investigations of the Formation Mechanism and Pressure Pulsation Characteristics of Pipeline Gas-Liquid Slug Flows

Zheng,

Xu,

et al. 2024

JMSE

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The pipeline system is widely used in marine engineering, and the formation mechanism and flow patterns of two-phase slug flows are of great significance for the optimal design of and vibration prevention in a complex pipeline system. Aiming at the above problems, this paper proposes a modeling and solving method for gas-liquid slug flows. First, a VOF-PLIC-based coupling gas-liquid slug flow transport model is conducted. Second, to reduce the fuzzy boundary between the gas-liquid coupling interfaces, an artificial compression term is added to the transport equations, and the formation and evolution mechanism of severe slugging flow in piping systems is investigated. The pressure pulsation and gas content characteristics of the gas-liquid coupling process are explored. Research results found that the slugging phenomenon occurs at the gas-liquid interface, where liquid slugging frequency reaches its peak. The pipeline system has prominent periodic characteristics of the slugging phenomenon, and the period decreases when the gas-phase converted speed rises; pressure fluctuation amplitude increases, and the gas-phase velocity change is the inducing factor for the drastic change of pressure fluctuation. The research results can offer theoretical references for optimal designs of and vibration prevention in marine pipeline systems.

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Dimensionless Analyses of Liquid–Liquid–Liquid Three-Phase Flow Patterns in a Confined Microchannel

Cited by 3 publications

References 43 publications

Effects of Rheological Properties of Non-Newtonian Middle Fluids on the Formation Dynamics of Double Emulsions in Coflowing Microfluidic Emulsification

Effects of Rheological Properties of Non-Newtonian Middle Fluids on the Formation Dynamics of Double Emulsions in Coflowing Microfluidic Emulsification

Numerical study of double emulsion generation in a flow-focusing microchannel by multiple-relaxation-time lattice Boltzmann method

Investigations of the Formation Mechanism and Pressure Pulsation Characteristics of Pipeline Gas-Liquid Slug Flows

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