Ladd Anthony J C, Kekre Rahul, Butler Jason E
Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611-6005, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Sep;80(3 Pt 2):036704. doi: 10.1103/PhysRevE.80.036704. Epub 2009 Sep 22.
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%.
本文旨在比较线性链状分子的格子玻尔兹曼模拟和布朗动力学模拟结果。我们系统地改变了可能影响格子玻尔兹曼模拟精度的参数，包括网格分辨率、温度、聚合物质量和流体粘度。通过对周期性和无界系统中不同长程相互作用的解析校正，将周期性边界条件的影响降至最低。发现格子玻尔兹曼方法得到的扩散系数和Rouse模式弛豫时间结果对温度不敏感，这表明流体动力学延迟效应较小。通过提高格子玻尔兹曼网格相对于聚合物尺寸的分辨率，获得了扩散系数和弛豫时间的收敛结果；这些结果与布朗动力学的结果在1%-2%的范围内相符。
