The heat flux vector for highly inhomogeneous nonequilibrium fluids in very narrow pores

Abstract

In this paper we present the results of nonequilibrium molecular dynamics simulations of an atomic fluid undergoing planar Poiseuille flow through a narrow slit pore. In particular we examine the heat flux vector for such a fluid and find that it displays weak oscillations with wavelengths that are characteristic of the van der Waals particle diameter. Furthermore, we examine the possibility of a coupling of the heat flux vector with the gradient of the square of the strain rate tensor and find that if such a coupling exists it would be undetectable by an examination of the heat flux vector alone. Its existence only manifests itself in the temperature profile, where a quadratic term would appear in addition to the usual quartic profile predicted by classical Navier–Stokes hydrodynamics.