Galliero Guillaume
Laboratoire des Fluides Complexes (UMR-5150 with CNRS and TOTAL), Université de Pau et des Pays de l'Adour, BP 1155, 64013 Pau Cedex, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 May;81(5 Pt 2):056306. doi: 10.1103/PhysRevE.81.056306. Epub 2010 May 6.
Using nonequilibrium molecular dynamics simulations on simple Lennard-Jones binary mixtures, we have studied the behavior of planar fluid-fluid interfaces undergoing shear flow. When the miscibility is low enough, a slip together with a partial depletion have been noticed at the interface between the two fluid phases. The slip length can reach a value equal to some molecular diameters and the corresponding interfacial viscosity can be two times smaller than the value in the bulk. It is shown how the omission of this slip may lead to flow-rate misevaluation when dealing with a multiphase flow in a nanoporous medium even for non polymer fluids. In addition, using the simulation results, a simple relation between interfacial tension and interfacial viscosity is proposed for the monoatomic systems studied in this work. Finally, it is shown that the interfacial viscosity cannot be fully accounted for by estimating the local viscosity deduced from the local thermodynamic properties of the interface.
通过对简单的 Lennard-Jones 二元混合物进行非平衡分子动力学模拟，我们研究了平面流体-流体界面在剪切流作用下的行为。当混溶性足够低时，在两个流体相之间的界面处会出现滑移以及部分耗尽现象。滑移长度可以达到等于若干分子直径的值，并且相应的界面粘度可能比本体中的值小两倍。结果表明，即使对于非聚合物流体，在处理纳米多孔介质中的多相流时，忽略这种滑移可能会导致流量评估错误。此外，利用模拟结果，针对本文研究的单原子系统，提出了界面张力与界面粘度之间的简单关系。最后，结果表明，通过估计从界面的局部热力学性质推导的局部粘度，无法完全解释界面粘度。
