Banetta Luca, Zaccone Alessio
Statistical Physics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, United Kingdom.
Department of Physics "A. Pontremoli", University of Milan, via Celoria 16, 20133 Milan, Italy.
Phys Rev E. 2019 May;99(5-1):052606. doi: 10.1103/PhysRevE.99.052606.
Determining the microstructure of colloidal suspensions under shear flows has been a challenge for theoretical and computational methods due to the singularly perturbed boundary-layer nature of the problem. Previous approaches have been limited to the case of hard-sphere systems and suffer from various limitations in their applicability. We present an alternative analytic scheme based on intermediate asymptotics which solves the Smoluchowski diffusion-convection equation including both intermolecular and hydrodynamic interactions. The method is able to recover previous results for the hard-sphere fluid and to predict the radial distribution function (rdf) of attractive fluids such as the Lennard-Jones (LJ) fluid. In particular, a new depletion effect is predicted in the rdf of the LJ fluid under shear. This method can be used for the theoretical modeling and understanding of real fluids subjected to flow, with applications ranging from chemical systems to colloids, rheology, plasmas, and atmospherical science.
由于该问题具有奇异摄动边界层性质，确定剪切流作用下胶体悬浮液的微观结构对理论和计算方法而言一直是一项挑战。先前的方法仅限于硬球系统的情况，并且在适用性方面存在各种限制。我们提出了一种基于中间渐近理论的替代解析方案，该方案求解了包含分子间和流体动力学相互作用的斯莫卢霍夫斯基扩散 - 对流方程。该方法能够重现硬球流体的先前结果，并预测诸如 Lennard-Jones（LJ）流体等吸引性流体的径向分布函数（rdf）。特别地，预测了剪切作用下 LJ 流体的 rdf 中存在一种新的耗尽效应。此方法可用于对受流动作用的真实流体进行理论建模和理解，其应用范围涵盖从化学系统到胶体、流变学、等离子体以及大气科学等领域。
