Objective molecular dynamics for atomistic simulation of macroscopic fluid motion

The method of Objective Molecular Dynamics (OMD) provides exact solutions of the equations of molecular dynamics for atoms filling all of space in non equilibrium situations. The method can be used to simulate families of incompressible, compressible and unsteady flows, also with time-dependent vorticity. In this paper we develop OMD as an efficient computational tool and introduce some of its applications. We apply the method to the evolution of compressible heat-conducting monoatomic gas under general incompressible flow, and to flow in a nanochannel having realistic atomistic solid boundaries. The macroscopic flows of OMD are exact solutions of the Navier-Stokes equation with Newtonian and Fourier models, and we make comparisons with these solutions. We also report the simulation of homoenergetic dilatational flow exhibiting condensation using OMD techniques. (c) 2023 Elsevier Inc. All rights reserved.