A microscopic particle image velocimetry method for studying the dynamics of immiscible liquid–liquid interactions in a porous micromodel

摘要: The development of an experimental protocol to investigate the flow field produced by interaction two immiscible liquids flowing through a porous network is reported. allows simultaneous quantification velocity distribution in multi-liquid system based on microscopic particle image velocimetry technique. challenges associated with this unique application are discussed, including two-liquid imaging and interface tracking, solutions that couple refractive index matching fluorescent signal separation described. technique was applied both single- flows two-dimensional pore comprising staggered array circular pillars wherein driven steady pressure gradient. Both drainage imbibition were considered herein focus fluid–fluid front migration effects owing passage interface. obtained for these two-liquid-phase scenarios revealed several peculiarities when compared reference case single-liquid-phase flow. In particular, instabilities interfacial processes propagate downstream perturb field, resulting dramatic differences from regular periodic paths typical steady-state, single-phase Additionally, does not restore previous patterns, but instead yields complex preferential mutually interact residual trapped pockets fluid. Such dynamical events must be quantified order properly model pore-scale physics central fully understanding wealth practical applications represented system.