We establish a comprehensive description of the patterns formed when a wetting liquid displaces a viscous fluid confined in a porous medium. Building on model microfluidic experiments, we evidence four imbibition scenarios all yielding different large-scale morphologies. Combining high-resolution imaging and confocal microscopy, we show that they originate from two liquid-entrainment transitions and a Rayleigh-Plateau instability at the pore scale. Finally, we demonstrate and explain the long-time coarsening of the resulting patterns.

中文翻译：

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多孔介质中的强制吸入：四重方案

我们建立了当润湿液置换受限于多孔介质中的粘性流体时形成的图案的全面描述。在模型微流体实验的基础上，我们证明了四种吸收场景均产生不同的大规模形态。结合高分辨率成像和共聚焦显微镜，我们显示它们源自两个液体夹带跃迁和在孔隙尺度上的瑞利高原不稳定性。最后，我们演示并解释了所产生模式的长期粗化。