Chaotic mixing induced by a magnetic chain in a rotating magnetic field
Chaotic mixing induced by a magnetic chain in a rotating magnetic field
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DOI：
10.1103/physreve.76.066303
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发表时间：
2007-12-01
影响因子：
2.4
通讯作者：
Meijer, Han E. H.
中科院分区：
文献类型：
--
作者：
Kang, Tae Gon;Hulsen, Martien A.;Meijer, Han E. H.
研究了旋转磁场作用下磁链的分裂与重组所引起的混沌混合。采用麦克斯韦应力张量和虚拟区域法相结合的直接模拟方法求解了含悬浮磁性颗粒的流动。链的运动显著地取决于梅森数（Ma），粘性力与磁力的比率。混沌度的特征在于最大李雅普诺夫指数。我们还及时跟踪两种流体的界面，并计算受梅森数影响的拉伸速率。混合的进展是可视化的通过示踪粒子跟踪方法，其特征在于离散的偏析强度。在梅森数的有限范围内，磁链旋转并断裂成更小的链，分离的链再次连接形成单链。链的重复拓扑变化导致最有效的方式混沌混合拉伸链断裂和折叠由于旋转流。
Chaotic mixing, induced by breakup and reformation of a magnetic chain under the influence of a rotating magnetic field, is studied. A direct simulation method combining the Maxwell stress tensor and a fictitious domain method is employed to solve flows with suspended magnetic particles. The motion of the chain is significantly dependent on the Mason number (Ma), the ratio of viscous force to magnetic force. The degree of chaos is characterized by the maximum Lyapunov exponents. We also track the interface of two fluids in time and calculate the rate of stretching as it is affected by the Mason number. The progress of mixing is visualized via a tracer particle-tracking method and is characterized by the discrete intensity of segregation. Within a limited range of Mason number, a magnetic chain rotates and breaks into smaller chains, and the detached chains connect again to form a single chain. The repeating topological changes of the chain lead to the most efficient way of chaotic mixing by stretching at chain breakup and folding due to rotational flows.