The raspberry model for hydrodynamic interactions revisited. I. Periodic arrays of spheres and dumbbells
The raspberry model for hydrodynamic interactions revisited. I. Periodic arrays of spheres and dumbbells
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DOI：
10.1063/1.4928502
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发表时间：
2015-08-28
影响因子：
4.4
通讯作者：
de Graaf, Joost
中科院分区：
文献类型：
--
作者：
Fischer, Lukas P.;Peter, Toni;de Graaf, Joost
所谓的“覆盆子”模型是指用于模拟胶体颗粒悬浮液动力学的混合晶格-玻尔兹曼和朗格万分子动力学方案，最初由Lobaskin和Dunweg [New J. Phys. 6,54(2004)]开发，其中使用离散的表面点来实现流体-颗粒耦合。这种技术已被用于许多胶体行为的模拟研究。然而，关于该模型的使用存在一些基本问题。在本文中，我们研究了与简单立方晶体中固体球体的解析表达式相比，覆盆子方法能够再现斯托克斯级流体动力相互作用的准确性。为此，我们考虑了传统上用于建立这些性质的数值实验的质量，并讨论了它们的缺点。我们证明了简单树莓模型再现的平移和旋转迁移率之间存在差异，并提出了一种通过添加内部耦合点在数值上弥补这一问题的方法。最后，我们研究了非凸形状，即胶体哑铃，并表明填充覆盆子模型复制了这种更复杂形状的所需流体动力学行为。de Graaf等人的研究仍在继续。化学。物理学报，143,084108(2015)]，其中我们在两个平行板的限制几何中考虑树莓模型。(C) 2015 AIP出版有限责任公司
The so-called "raspberry" model refers to the hybrid lattice-Boltzmann and Langevin molecular dynamics scheme for simulating the dynamics of suspensions of colloidal particles, originally developed by Lobaskin and Dunweg [New J. Phys. 6, 54 (2004)], wherein discrete surface points are used to achieve fluid-particle coupling. This technique has been used in many simulation studies on the behavior of colloids. However, there are fundamental questions with regards to the use of this model. In this paper, we examine the accuracy with which the raspberry method is able to reproduce Stokes-level hydrodynamic interactions when compared to analytic expressions for solid spheres in simple-cubic crystals. To this end, we consider the quality of numerical experiments that are traditionally used to establish these properties and we discuss their shortcomings. We show that there is a discrepancy between the translational and rotational mobility reproduced by the simple raspberry model and present a way to numerically remedy this problem by adding internal coupling points. Finally, we examine a non-convex shape, namely, a colloidal dumbbell, and show that the filled raspberry model replicates the desired hydrodynamic behavior in bulk for this more complicated shape. Our investigation is continued in de Graaf et al. [J. Chem. Phys. 143, 084108 (2015)], wherein we consider the raspberry model in the confining geometry of two parallel plates. (C) 2015 AIP Publishing LLC.