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Accelerated Stokesian dynamics: Brownian motion

Banchio, Adolfo J. and Brady, John F. (2003) Accelerated Stokesian dynamics: Brownian motion. Journal of Chemical Physics, 118 (22). pp. 10323-10332. ISSN 0021-9606. http://resolver.caltech.edu/CaltechAUTHORS:BANjcp03

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Abstract

A new Stokesian dynamics (SD) algorithm for Brownian suspensions is presented. The implementation is based on the recently developed accelerated Stokesian dynamics (ASD) simulation method [Sierou and Brady, J. Fluid Mech. 448, 115 (2001)] for non-Brownian particles. As in ASD, the many-body long-range hydrodynamic interactions are computed using fast Fourier transforms, and the resistance matrix is inverted iteratively, in order to keep the computational cost O(N log N). A fast method for computing the Brownian forces acting on the particles is applied by splitting them into near- and far-field contributions to avoid the O(N3) computation of the square root of the full resistance matrix. For the near-field part, representing the forces as a sum of pairwise contributions reduces the cost to O(N); and for the far-field part, a Chebyshev polynomial approximation for the inverse of the square root of the mobility matrix results in an O(N1.25 log N) computational cost. The overall scaling of the method is thus roughly of O(N1.25 log N) and makes possible the simulation of large systems, which are necessary for studying long-time dynamical properties and/or polydispersity effects in colloidal dispersions. In this work the method is applied to study the rheology of concentrated colloidal suspensions, and results are compared with conventional SD. Also, a faster approximate method is presented and its accuracy discussed.


Item Type:Article
Additional Information:©2003 American Institute of Physics. (Received 21 November 2002; accepted 12 March 2003) This research was supported in part by NSF Cooperative Agreement No. ACI-9619020 through computing resources provided by the National Partnership for Advanced Computational Infrastructure at the San Diego Supercomputer Center and by Grant No. NAG8-1661 from NASA. A.J.B. also acknowledges support form Fundacio´n Antorchas (Project Nos. 13956-43 and 13927-3).
Subject Keywords:Brownian motion; suspensions; acceleration; fast Fourier transforms; rheology; Chebyshev approximation; polynomials
Record Number:CaltechAUTHORS:BANjcp03
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:BANjcp03
Alternative URL:http://dx.doi.org/10.1063/1.1571819
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1841
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:20 Feb 2006
Last Modified:26 Dec 2012 08:46

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