A comparison of the static and dynamic properties of a semi-flexible polymer using lattice-Boltzmann and Brownian dynamics simulations

TL;DR

This study compares lattice-Boltzmann and Brownian dynamics simulations of semi-flexible polymers, analyzing how simulation parameters affect accuracy and demonstrating convergence of results with increased grid resolution.

Contribution

It systematically evaluates the effects of simulation parameters on lattice-Boltzmann accuracy and shows convergence with Brownian dynamics for polymer properties.

Findings

Lattice-Boltzmann results are insensitive to temperature.

Results converge with increased grid resolution.

Lattice-Boltzmann and Brownian dynamics agree within 1-2%.

Abstract

The aim of this paper is to compare results from lattice-Boltzmann and Brownian dynamics simulations of linear chain molecules. We have systematically varied the parameters that may affect the accuracy of the lattice-Boltzmann simulations, including grid resolution, temperature, polymer mass, and fluid viscosity. The effects of the periodic boundary conditions are minimized by an analytic correction for the different long-range interactions in periodic and unbounded systems. Lattice-Boltzmann results for the diffusion coefficient and Rouse mode relaxation times were found to be insensitive to temperature, which suggests that effects of hydrodynamic retardation are small. By increasing the resolution of the lattice-Boltzmann grid with respect to the polymer size, convergent results for the diffusion coefficient and relaxation times were obtained; these results agree with Brownian dynamics to within 1--2%.