Menon Gautam I, Ramaswamy Sriram
The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600 113, India.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Jun;79(6 Pt 1):061108. doi: 10.1103/PhysRevE.79.061108. Epub 2009 Jun 11.
Collections of non-Brownian particles suspended in a viscous fluid and subjected to oscillatory shear at very low Reynolds number have recently been shown to exhibit a remarkable dynamical phase transition separating reversible from irreversible behavior as the strain amplitude or volume fraction are increased. We present a simple model for this phenomenon, based on which we argue that this transition lies in the universality class of the conserved directed percolation models. This leads to predictions for the scaling behavior of a large number of experimental observables. Non-Brownian suspensions under oscillatory shear may thus constitute the first experimental realization of an inactive-active phase transition which is not in the universality class of conventional directed percolation.
最近研究表明，悬浮在粘性流体中且在极低雷诺数下受到振荡剪切作用的非布朗粒子集合，随着应变幅度或体积分数的增加，会呈现出一种显著的动态相变，将可逆行为与不可逆行为区分开来。我们提出了一个关于此现象的简单模型，并据此认为这种相变属于守恒定向渗流模型的普适类。这导致了对大量实验可观测量标度行为的预测。因此，振荡剪切作用下的非布朗悬浮液可能构成了一种非活性 - 活性相变的首个实验实现，该相变不属于传统定向渗流的普适类。
