Rotne–Prager–Yamakawa approximation for different-sized particles in application to macromolecular bead models
Rotne–Prager–Yamakawa approximation for different-sized particles in application to macromolecular bead models
复制标题
不同尺寸颗粒的 Rotne-Prager-Yamakawa 近似在大分子珠模型中的应用
DOI：
10.1017/jfm.2013.668
复制
发表时间：
2014
影响因子：
3.7
通讯作者：
P. Szymczak
中科院分区：
文献类型：
--
作者：
P. Żuk;E. Wajnryb;K. Mizerski;P. Szymczak
摘要Rotne-Prager-Yamakawa（RPY）近似是一种常用的方法来模拟低雷诺数下粘性流体中悬浮的小球形颗粒之间的流体动力学相互作用。然而，当粒子重叠时，RPY张量失去其正定性，这导致在布朗动力学模拟中的数值问题以及使用珠建模的刚性大分子的流体动力学性质的计算中的错误。这些问题可以通过对RPY张量进行正则化修正来避免;然而，到目前为止，这些修正只针对等尺寸粒子。在这里，我们将展示如何推广的RPY方法的情况下，重叠的球形粒子的不同半径，并提出了完整的一套这样的系统的迁移率矩阵。与以前的特别方法相比，我们的方法依赖于在球体表面上的力密度的直接积分，从而自动提供了正确的限制行为的流动性的接触领域和一个完整的重叠，一个领域沉浸在另一个。然后，这种方法可以用来计算复杂的大分子的流体动力学特性，使用珠模型与重叠，不同大小的珠，我们用一个例子来说明。
Abstract The Rotne–Prager–Yamakawa (RPY) approximation is a commonly used approach to model the hydrodynamic interactions between small spherical particles suspended in a viscous fluid at a low Reynolds number. However, when the particles overlap, the RPY tensors lose their positive definiteness, which leads to numerical problems in the Brownian dynamics simulations as well as errors in calculations of the hydrodynamic properties of rigid macromolecules using bead modelling. These problems can be avoided by using regularizing corrections to the RPY tensors; so far, however, these corrections have only been derived for equal-sized particles. Here we show how to generalize the RPY approach to the case of overlapping spherical particles of different radii and present the complete set of mobility matrices for such a system. In contrast to previous ad hoc approaches, our method relies on the direct integration of force densities over the sphere surfaces and thus automatically provides the correct limiting behaviour of the mobilities for the touching spheres and for a complete overlap, with one sphere immersed in the other one. This approach can then be used to calculate hydrodynamic properties of complex macromolecules using bead models with overlapping, different-sized beads, which we illustrate with an example.
影响因子：
3.4
作者：
Arya, Gaurav;Zhang, Qing;Schlick, Tamar
通讯作者：
Schlick, Tamar