Multiphase microflow

Rahman MT, Fukuyama T, Kamata N et al (2006) Low pressure Pd-catalyzed carbonylation in an ionic liquid using a multiphase microflow system. Chem Commun 21 2236-2238... 

Control of multiphase microflows is an important basic technology for integration of MUOs. Therefore, control methods for the stable phase separation of the multiphase microflows in a wide range of the flow... 

Multiphase microflows are dominated by pressures (Aota et al., 2007a, 2009a). One important parameter needed to describe the multiphase microflows is the pressure that drives the fluids. The pressure decreases in the downstream part of the flow because of the fluids viscosity. When two fluids in contact with one another have different viscosities, the pressure difference (APfiow) between the two phases is a function of the contact length and the flow velocity. Another important parameter is the Laplace pressure (APLapiace) caused by the interfacial tension between two phases. The position of the interface is fixed within a point in the microchannel by the balance established between the APLaplace and APFlow. 

C. Choi, H. Yi, S. Hwang, D. Weitz, and C. Lee, Microfluidic fabrication of complex-shaped microfibers by liquid template-aided multiphase microflow, Lab on a Chip, 11, 1477-1483, 2011. 

Kai Wang, Jianhong Xu, Guotao Liu, and Guangsheng Luo, Role of Intefacial Force on Multiphase Microflow—An Important Meso-Sdentific Issue... 

Aota, A., Mawatari, K., Kitamori, T. (2009). Parallel multiphase microflows Fundamental physics, stabilization methods and applications. Lab on a Chip, 9, 2470-2476. 

Fundamental principles and CFD simulation of multiphase microflows remain to be further investigated. 

In this section, we first introduce interfadal tension and consider a resting fluid interface, and discuss its interaction with a microchannel wall. We continue with consideration of dynamically moving fluid interfaces that are relevant to multiphase microflows. The diEFerent body forces, gravitational, viscous and inertial effects are... 

In flowing systems, the complex interplay between interfacial, gravitational, viscous and inertial forces is responsible for a variety of phase distributions and flow patterns. The dominant interfadal forces combined with the laminar nature of the flow result in very regularly shaped gas-liquid and liquid-liquid interfaces characteristic of multiphase microflows. Courbin et al. described dynamic wetting morphologies of a flat surface that is microstructured with a forest of posts upon droplet impact [44], Eijkel and co-workers [42, 48] provided a more general review of surface tension effects in the context of nanofluidic systems. The importance of interfadal forces with respect to gravity is described by the dimensionless Bond number. 

Ranking the importance of different forces helps in categorizing the increasing number of experimental studies with the ultimate goal to predid multiphase flow behavior in microchannel networks and formulate guidelines for their design. Multiphase microflows are charaderized by the ratio of viscous to surface forces, the capillary number (Co) and by the ratio of fluid viscosities ... 

The dynamic nature of multiphase microflows imposes unique requirements on the time resolution of the flow characterization techniques. Table 1.1 summarizes different experimental techniques for characterizing microscale multiphase flow and also the spatial and temporal measurement resolutions. Intmsive measurement probes are generally not an option for micro- and nanofluidic systems. 

Role of Interfacial Force on Multiphase Microflow—An Important Meso-Scientific Issue... 

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