Computer simulation of structures and distributions of particles in MAGIC fluid
Computer simulation of structures and distributions of particles in MAGIC fluid
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DOI：
10.1016/j.jmmm.2005.08.015
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发表时间：
2006-07
影响因子：
2.7
通讯作者：
Yongsheng Zhu;N. Umehara;Y. Ido;A. Sato
中科院分区：
文献类型：
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作者：
Yongsheng Zhu;N. Umehara;Y. Ido;A. Sato
MAG-netic Intelligent Compound（MAG-netic Intelligent Compound）是一种含有磁性颗粒（MP）和微米级磨粒（AP、PPR）的固化磁性铁磁流体（MF）。在MAGIC流体的冷却过程中，通过施加磁场可以控制APs在MAGIC中的分布。本文采用Stokes动力学（SD）模拟方法，初步研究了磁场、颗粒尺寸和浓度对MAGIC流体中MP最终结构和AP分布的影响。模拟结果表明，MPs在MAGIC流体中更倾向于形成条状结构，其原因主要是MPs与MAGIC流体之间存在较强的偶极相互作用。在弱磁场下，磁微粒倾向于形成大的团聚体，而在强磁场下，磁微粒倾向于形成链状或条状结构;在低浓度MAGIC流体中，磁微粒不形成长链状或条状结构;在大尺寸磁微粒中，磁微粒形成纯壁状结构。用均匀性系数对磨料粒子的分布进行评价，结果表明，强磁场、高浓度、小粒径的磨料粒子可以使磨料粒子在MAGIC液中分布更加均匀，MAGIC液中磨料粒子的均匀性比普通磨具中的均匀性提高约10%。
MAGIC (MAG-netic Intelligent Compound) is a solidified magnetic ferrofluid (MF) containing both magnetic particles (MPs) and abrasive particles (APs, nonmagnetic) of micron size. The distribution of APs in MAGIC can be controlled by applying a magnetic field during cooling process of MAGIC fluid. In this paper, the influences of magnetic field, size and concentration of particles on the final structures of MPs and the distributions of APs in MAGIC fluid are preliminarily investigated using Stokesian dynamic (SD) simulation method. Simulation results show that MPs prefer to form strip-like structures in MAGIC fluid, the reason for this phenomenon is mainly attributed to the strong dipolar interactions between them. It is also found that MPs prefer to form big agglomerations in weak magnetic field while chains and strip-like structures in strong magnetic field; no long chains or strip-like structures of MPs are observed in low-concentration MAGIC fluid; and for big-size MPs, pure wall-like structures are formed. Evaluation on the distribution of APs with uniformity coefficient shows that strong magnetic field, high concentration and small-size particles can induce more uniform distribution of APs in MAGIC fluid, the uniformity of APs in MAGIC is about 10% higher than that in normal grinding tools.