BRIDGING MICRO AND MACRO SCALES IN FLUIDS

摘要

This paper presents coarse-graining methodologies for the passage from Molecular Dynamics (MD) models of fluids to the Navier-Stokes equations via an intermediate scale model. The microscopic and macroscopic descriptions of fluids are bridged by taking spatial and temporal averages of atomic quantities. The result is a set of discrete stochastic equations governing the evolution of coarsegrained mass, momentum, and energy, which can be shown to converge to a finite-difference representation of the Navier-Stokes equations in the large scale limit.