De Corato M, Greco F, D'Avino G, Maffettone P L
Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Universitá di Napoli Federico II, P.le Tecchio 80, 80125 Naples, Italy.
Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio 80, 80125 Naples, Italy.
J Chem Phys. 2015 May 21;142(19):194901. doi: 10.1063/1.4920981.
In this work, we study in detail the hydrodynamics and the Brownian motions of a spheroidal particle suspended in a Newtonian fluid near a flat rigid wall. We employ 3D Finite Element Method (FEM) simulations to compute how the mobility tensor of the spheroid varies with both the particle-wall separation distance and the particle orientation. We then study the Brownian motion of the spheroid by means of a discretized Langevin equation. We specifically focus on the additional drift terms arising from the position and orientational dependence of the mobility matrix. In this respect, we also propose a numerically convenient approximation of the orientational divergence of the mobility matrix that is required in the solution of the Langevin equation. Our results illustrate that both hydrodynamics and Brownian motions of a spheroidal particle near a confining wall display novel features from those of a sphere in the same type of confinement.
在这项工作中,我们详细研究了悬浮在靠近平坦刚性壁的牛顿流体中的椭球体颗粒的流体动力学和布朗运动。我们采用三维有限元方法(FEM)模拟来计算椭球体的迁移率张量如何随颗粒与壁的分离距离以及颗粒取向而变化。然后,我们通过离散化的朗之万方程研究椭球体的布朗运动。我们特别关注由迁移率矩阵的位置和取向依赖性产生的附加漂移项。在这方面,我们还提出了朗之万方程求解中所需的迁移率矩阵取向散度的数值方便近似。我们的结果表明,在受限壁附近的椭球体颗粒的流体动力学和布朗运动都表现出与相同类型受限情况下球体的流体动力学和布朗运动不同的新特征。