论文标题
多孔介质中混沌混合的标量签名
Scalar signatures of chaotic mixing in porous media
论文作者
论文摘要
稳定的层流通过多孔培养基自发地产生毛孔的混乱，对一系列运输，反应性和生物学过程具有定性的影响。在这些不透明的环境中，对混合动力学的表征和理解是一个重大的挑战。我们通过基于通过多孔介质样品产生的标量签名的高分辨率成像来开发一种新技术来解决这个问题。由于混沌流中粒子轨迹的快速去相关，在多孔材料之外测量的标量图像代表了原位混合动力学。我们提出了一个理论框架，用于基于拉格朗日拉伸理论扩展到相关的聚集的估计指数。该方法提供了大量多孔材料中混沌混合动力学的完整表征。
Steady laminar flows through porous media spontaneously generate Lagrangian chaos at pore scale, with qualitative implications for a range of transport, reactive and biological processes. The characterization and understanding of mixing dynamics in these opaque environments is an outstanding challenge. We address this issue by developing a novel technique based upon high-resolution imaging of the scalar signature produced by push-pull flows through porous media samples. Owing to the rapid decorrelation of particle trajectories in chaotic flows, the scalar image measured outside the porous material is representative of in-situ mixing dynamics. We present a theoretical framework for estimation of the Lyapunov exponent based on extension of Lagrangian stretching theories to correlated aggregation. This method provides a full characterization of chaotic mixing dynamics in a large class of porous materials.
