Scuola di Scienze e Tecnologie, Università di Camerino, Via Madonna delle Carceri, 62032, Camerino, INFN Perugia, Italy.
J Chem Phys. 2011 Feb 14;134(6):064118. doi: 10.1063/1.3528221.
A multicomponent extension of our recent theory of simple fluids [U. M. B. Marconi and S. Melchionna, J. Chem. Phys. 131, 014105 (2009)] is proposed to describe miscible and immiscible liquid mixtures under inhomogeneous, nonsteady conditions typical of confined fluid flows. We first derive from a microscopic level the evolution equations of the phase space distribution function of each component in terms of a set of self-consistent fields, representing both body forces and viscous forces (forces dependent on the density distributions in the fluid and on the velocity distributions). Second, we numerically solve the resulting governing equations by means of the lattice Boltzmann method, whose implementation contains novel features with respect to existing approaches. Our model incorporates hydrodynamic flow, diffusion, surface tension, and the possibility for global and local viscosity variations. We validate our model by studying the bulk viscosity dependence of the mixture on concentration, packing fraction, and size ratio. Finally, we consider inhomogeneous systems and study the dynamics of mixtures in slits of molecular thickness and relate structural and flow properties.
我们最近提出了一种多组分扩展理论，用于描述简单流体[U. M. B. Marconi 和 S. Melchionna，J. Chem. Phys. 131, 014105 (2009)]，以描述在受限流体流动中常见的不均匀、非稳态条件下的混溶性和不混溶性液体混合物。我们首先从微观层面出发，根据一组自洽场（代表体力和粘性力（取决于流体中的密度分布和速度分布的力））推导出每个组分的相空间分布函数的演化方程。其次，我们通过格子玻尔兹曼方法数值求解得到的控制方程，其实现相对于现有方法具有新颖的特点。我们的模型包含了流体力学流动、扩散、表面张力以及全局和局部粘度变化的可能性。我们通过研究混合物的体粘度对浓度、堆积分数和尺寸比的依赖性来验证我们的模型。最后，我们考虑非均匀系统，并研究狭缝中混合物的动力学，以及结构和流动性质的关系。
