LAUSR

Abstract In this paper, we analytically investigate the influence of the nanochannel width on mass transfer characteristics through the rough nanochannel by using non–equilibrium multiscale molecular dynamics simulation. The mass transfer characteristics are analyzed by fitting the curve correlation between the diffusion coefficient and nanochannel width. The diffusion coefficient is calculated using the revised Green–Kubo relation in different nanochannels. The numerical results demonstrate that the relationship between diffusion coefficient and the inverse of nanochannel width is parabolic. Moreover, the diffusion coefficients show significant variations in the small rough nanochannel, and gradually approach the values of bulk system with increasing the width of nanochannel. In addition, to explore its mechanism, the local atom number density, velocity profile, velocity autocorrelation function, the escape rate of molecule, local diffusion coefficient and projection radial distribution function are given in different widths of nanochannel under given boundary condition. Simulation results show that the local structure and number density of fluid influence the transfer mass characteristics. These results of this work may be conducive to further understand the mass transfer behaviors of nanofluidics, and guide the optimal design of nano–devices.