Satoh A, Chantrell RW, Coverdale GN, Kamiyama Si
Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263, Japan
J Colloid Interface Sci. 1998 Jul 15;203(2):233-48. doi: 10.1006/jcis.1998.5498.
We have investigated the behavior of clusters of ferromagnetic particles in a colloidal dispersion subjected to a simple shear flow. To do so, the Stokesian dynamics method has been used under the assumption that the effect of Brownian motion is negligible. For the case of no shear flow, the aggregate structures obtained by the Stokesian dynamics simulations agree well with Monte Carlo results qualitatively. We can, therefore, conclude that the Stokesian dynamics simulations can capture thick chainlike clusters without introducing a specific clustering algorithm, which is indispensable for Monte Carlo simulations. The behavior of the thick chainlike clusters in a simple shear flow is summarized as follows. The thick chainlike clusters decline in the shear flow direction as time advances. Since longer clusters experience larger shear forces, it is difficult for them to survive in such a situation. The thick chainlike clusters, therefore, dissociate into some short clusters. Such clusters are relatively stable in a shear flow, so that they do not decrease significantly any more. The viscosities have a strong relationship with the internal structures of the aggregates. The instantaneous viscosities, therefore, fluctuate significantly for the case of the thick chainlike clusters. Copyright 1998 Academic Press.
我们研究了处于简单剪切流中的胶态分散体中铁磁颗粒簇的行为。为此，在布朗运动的影响可忽略不计的假设下，采用了斯托克斯动力学方法。对于无剪切流的情况，通过斯托克斯动力学模拟得到的聚集体结构在定性上与蒙特卡罗结果吻合良好。因此，我们可以得出结论，斯托克斯动力学模拟无需引入特定的聚类算法就能捕捉到粗链状簇，而这对于蒙特卡罗模拟来说是必不可少的。粗链状簇在简单剪切流中的行为总结如下。随着时间的推移，粗链状簇在剪切流方向上逐渐减少。由于较长的簇受到的剪切力更大，它们在这种情况下难以存活。因此，粗链状簇会解离成一些短簇。此类簇在剪切流中相对稳定，所以它们不会再显著减少。粘度与聚集体的内部结构有很强的关系。因此，对于粗链状簇的情况，瞬时粘度会有显著波动。版权所有1998年学术出版社。
