论文标题
弹性湍流在多孔介质中产生异常的流动性
Elastic turbulence generates anomalous flow resistance in porous media
论文作者
论文摘要
各种过程依赖于通过多孔介质的聚合物溶液的粘性流动。在许多情况下，在多孔介质中，宏观流动阻力突然增加了阈值流速以上 - 但在散装溶液中不超过。半个多世纪以来一直是一个难题的原因。在这里，通过直接可视化透明的3D多孔介质中的流动，我们证明了这种异常增加是由于弹性不稳定性的发作。我们确定不稳定的流动波动散发的能量会随着孔的变化而变化，从而产生了整个介质的流动阻力的异常增加。因此，通过将不稳定流量的孔尺度发作与宏观运输联系起来，我们的工作提供了预测和控制聚合物溶液流量的普遍适用的指南。
Diverse processes rely on the viscous flow of polymer solutions through porous media. In many cases, the macroscopic flow resistance abruptly increases above a threshold flow rate in a porous medium---but not in bulk solution. The reason why has been a puzzle for over half a century. Here, by directly visualizing the flow in a transparent 3D porous medium, we demonstrate that this anomalous increase is due to the onset of an elastic instability. We establish that the energy dissipated by the unstable flow fluctuations, which vary across pores, generates the anomalous increase in flow resistance through the entire medium. Thus, by linking the pore-scale onset of unstable flow to macroscopic transport, our work provides generally-applicable guidelines for predicting and controlling polymer solution flows.
