N log N method for hydrodynamic interactions of confined polymer systems:: Brownian dynamics
N log N method for hydrodynamic interactions of confined polymer systems:: Brownian dynamics
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DOI：
10.1063/1.2358344
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发表时间：
2006-10-28
影响因子：
4.4
通讯作者：
Graham, Michael D.
中科院分区：
文献类型：
--
作者：
Hernandez-Ortiz, Juan P.;de Pablo, Juan J.;Graham, Michael D.
提出了一种布朗动力学模拟技术，其中基于傅立叶的NlogN方法用于计算两个平行壁之间的受限流动聚合物系统中的流体动力学相互作用。采用自洽的粗粒度朗之万描述的聚合物动力学的聚合物珠被视为点力。流体动力学相互作用，因此包括在扩散张量通过绿色的功能形式主义。绿色函数的计算基于Mucha [J. Fluid Mech.501，71（2004）]开发的用于沉积颗粒的方法的推广。一个傅立叶级数表示的Stokeslet，满足无滑移边界条件的墙壁，这种表示是安排在这样一种方式，珠珠相互作用的总O（N-2）的贡献计算在O（N log N）算法。使用Fixman [Macromolecules 19，1195（1986）; 19，1204（1986）]提出的用于扩散张量的平方根的切比雪夫多项式近似来计算布朗项。建议的布朗动力学模拟方法的规模为O（N-1.25 log N）。无限稀释系统的哑铃的结果，以验证过去的预测，并检查所提出的方法的性能和数值的一致性。(c)2006年，美国物理学会。
A Brownian dynamics simulation technique is presented where a Fourier-based N log N approach is used to calculate hydrodynamic interactions in confined flowing polymer systems between two parallel walls. A self-consistent coarse-grained Langevin description of the polymer dynamics is adopted in which the polymer beads are treated as point forces. Hydrodynamic interactions are therefore included in the diffusion tensor through a Green's function formalism. The calculation of Green's function is based on a generalization of a method developed for sedimenting particles by Mucha [J. Fluid Mech. 501, 71 (2004)]. A Fourier series representation of the Stokeslet that satisfies no-slip boundary conditions at the walls is adopted; this representation is arranged in such a way that the total O(N-2) contribution of bead-bead interactions is calculated in an O(N log N) algorithm. Brownian terms are calculated using the Chebyshev polynomial approximation proposed by Fixman [Macromolecules 19, 1195 (1986); 19, 1204 (1986)] for the square root of the diffusion tensor. The proposed Brownian dynamics simulation methodology scales as O(N-1.25 log N). Results for infinitely dilute systems of dumbbells are presented to verify past predictions and to examine the performance and numerical consistency of the proposed method. (c) 2006 American Institute of Physics.