High-Frequency Elastic Moduli of Simple Fluids

Publisher Website
Google Scholar
Abstract
This article presents a calculation of the infinite‐frequency elastic moduli of monatomic fluids. When the intermolecular potential has the standard Lennard‐Jones form, the elastic moduli are shown to be related to the pressure and internal energy of the fluid. Numerical values of the elastic moduli at various densities and temperatures are presented in tabular and graphical form. An identity is derived relating the shear and bulk moduli of any isotropic material in which particles interact by means of two‐body central forces; this is a generalization of the familiar Cauchy identity occurring in the theory of elasticity of solids. The approach is based on analysis of the high‐frequency limit of exact time‐correlation function expressions for shear and bulk viscosity.