Transport Properties Of Liquids In Narrow Pores

Download or read book Transport Properties of Liquids in Narrow Pores written by Sanjeev Sharma and published by . This book was released on 1994 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Local mechanism for flow processes through porous media transport phenomena in catalysts, fluidisation of granular materials, suspension rheology, etc., are difficult to study experimentally and are inadequately described by approximations of continuum fluid mechanics. In the present approach, molecular dynamics (I\ID) simulations of the effects of solid surfaces on the transport properties of a Lennard-Jones model liquid are desclibed. Transport properties of the model liquid have been determined from the stress correlation functions for both homogeneous liquid and in narrow pores of molecular dimensions. Viscosity profiles are defined by means of a resolution of the total stress tensor and its autocorrelation function into its auto- and cross-components of single molecules. This enables a precise definition of viscosity profiles and provides a method of determination from MD simulations of the interfacial regions. Preliminary shear viscosity profiles for liquids in periodic rectangular cavities (between two semi-infinite walls) have been obtained for both transverse and longitudinal components . Profiles of these transport coefficients have no direct experimentally accessible counterparts, but could be useful for bulk fluid mechanics predictions. Results have been obtained for (i) a hard, elastic wall-molecule interaction and (ii) a Lennard-Jones (10-4) wall. Elongational viscosities, which have not previously been investioated via MD correlation functions have also been computed for both homoceneous fluid and interfacial systems. The results are discussed in relation to current experimentation of interfacial viscosities (includina recent NEMD studies) and the continuum mechanics of flow in porous media.