Coarse-grained forms for equations describing the microscopic motion of particles in a fluid

Das, Shankar P. ; Yoshimori, Akira (2013) Coarse-grained forms for equations describing the microscopic motion of particles in a fluid Physical Review E - Statistical, Nonlinear and Soft Matter Physics, 88 (4). Article ID 043008. ISSN 1539-3755

Full text not available from this repository.

Official URL: http://journals.aps.org/pre/abstract/10.1103/PhysR...

Related URL: http://dx.doi.org/10.1103/PhysRevE.88.043008

Abstract

Exact equations of motion for the microscopically defined collective density ρˆ(x,t) and the momentum density gˆ(x,t) of a fluid have been obtained in the past starting from the corresponding Langevin equations representing the dynamics of the fluid particles. In the present work we average these exact equations of microscopic dynamics over the local equilibrium distribution to obtain stochastic partial differential equations for the coarse-grained densities with smooth spatial and temporal dependence. In particular, we consider Dean's exact balance equation for the microscopic density of a system of interacting Brownian particles to obtain the basic equation of the dynamic density functional theory with noise. Our analysis demonstrates that on thermal averaging the dependence of the exact equations on the bare interaction potential is converted to dependence on the corresponding thermodynamic direct correlation functions in the coarse-grained equations.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:99423
Deposited On:28 Jul 2016 12:30
Last Modified:28 Jul 2016 12:30

Repository Staff Only: item control page