Binary collision contribution to the longitudinal current correlation function of dense fluids

Abstract

An expression for the binary collision contribution to the first-order space-time memory function of the longitudinal current correlation function has been obtained by using the cluster expansion technique for a fluid whose particles are interacting through a continuous potential. This expression involves the radial distribution function and time dependence of the position, momentum, and acceleration vectors of the particles. The long-wavelength limit of the expression is obtained for use in studying the longitudinal and bulk viscosities of fluid. It is found that for the hard-sphere case, our method provides expressions for the longitudinal and bulk viscosities that agree with Enskog results.