Cottin Christophe, Bodiguel Hugues, Colin Annie
Université Bordeaux, LOF, UMR 5258, F-33600 Pessac, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Aug;84(2 Pt 2):026311. doi: 10.1103/PhysRevE.84.026311. Epub 2011 Aug 10.
This paper presents some experimental results on two-phase flows in model two-dimensional (2D) porous media with different wetting properties. Standard microfluidic techniques are used to fabricate the 2D micromodels that consist of a network of straight microchannels having heterogeneous sizes. The invasion mechanism is analyzed quantitatively for partial and total wetting conditions, and for various stable viscosity ratios and capillary pressure heterogeneity. For capillary numbers ranging from 10(-7) to 10(-2), we observe a transition between capillary fingering and a stable front. The capillary fingering regime exhibits differences between partial and complete wetting systems: The front width in complete wetting is larger. Simple models are proposed to account for these regimes and indicate that the differences between the systems are likely to be due to the flow of the displaced fluid in the complete wetting situation.
本文展示了在具有不同润湿性的二维（2D）模型多孔介质中两相流的一些实验结果。采用标准微流控技术制作二维微模型，该模型由尺寸各异的直微通道网络组成。针对部分润湿和完全润湿条件，以及各种稳定的粘度比和毛细管压力非均质性，对侵入机制进行了定量分析。对于毛细管数范围从10^(-7)到10^(-2)，我们观察到毛细管指进和稳定前沿之间的转变。毛细管指进状态在部分润湿和完全润湿系统之间表现出差异：完全润湿时的前沿宽度更大。提出了简单模型来解释这些状态，并表明系统之间的差异可能是由于完全润湿情况下被驱替流体的流动所致。
