Donado F, Sausedo-Solorio J M, Moctezuma R E
Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Pachuca 42184, Hidalgo, México.
CONACYT-Instituto de Física "Manuel Sandoval Vallarta", Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, 78000 San Luis Potosí, S.L.P., México.
Phys Rev E. 2017 Feb;95(2-1):022601. doi: 10.1103/PhysRevE.95.022601. Epub 2017 Feb 3.
We study a two-dimensional nonvibrating granular system as a model of a magnetorheological fluid. The system is composed of magnetic steel particles on a horizontal plane under a vertical sinusoidal magnetic field and a horizontal static magnetic field. When the amplitude of the horizontal field is zero, we find that the motion of the particles has characteristics similar to those of Brownian particles. A slowing down of the dynamics is observed as the particle concentration increases or the magnitude of the vertical magnetic field decreases. When the amplitude of the horizontal field is nonzero, the particles interact through effective dipolar interactions. Above a threshold in the amplitude of the horizontal field, particles form chains that become longer and more stable as time increases. For some conditions, at short time intervals, the average chain length as a function of time exhibits scaling behavior. The chain length distribution at a given time is a decreasing exponential function. The behavior of this granular system is consistent with theoretical and experimental results for magnetorheological fluids.
我们研究一个二维非振动颗粒系统，将其作为磁流变液的模型。该系统由水平面上的磁性钢颗粒组成，处于垂直正弦磁场和水平静磁场之下。当水平场的振幅为零时，我们发现颗粒的运动具有与布朗粒子相似的特征。随着颗粒浓度增加或垂直磁场强度减小，动力学过程会变慢。当水平场的振幅不为零时，颗粒通过有效的偶极相互作用相互作用。在水平场振幅超过阈值时，颗粒形成链条，随着时间增加，链条变得更长且更稳定。在某些条件下，在短时间间隔内，平均链长随时间的变化呈现标度行为。给定时间的链长分布是一个递减的指数函数。这个颗粒系统的行为与磁流变液的理论和实验结果一致。
