Role of three-body interactions in formation of bulk viscosity in liquid argon

Abstract

With the aim of locating the origin of discrepancy between experimental and computer simulation results on bulk viscosity of liquid argon, a molecular dynamic simulation of argon interacting via ab initio pair potential and triple-dipole three-body potential has been undertaken. Bulk viscosity, obtained using Green-Kubo formula, is different from the values obtained from modeling argon using Lennard-Jones potential, the former being closer to the experimental data. The conclusion is made that many-body inter-atomic interaction plays a significant role in formation of bulk viscosity.

Bulk viscosity of gaseous argon from molecular dynamics simulations

“…(B) Many-body interactions do not noticeably affect the bulk viscosity in dilute states, contrary to the previously investigated case of dense fluids [72].…”

“…Such a coarsegraining procedure, based on the Henderson theorem [67], is not necessarily applicable for nonequilibrium and inhomogeneous systems. Many-body interactions may affect the transport and interfacial properties of the fluids, as reported for a self-diffusion coefficient [68], shear viscosity [68][69][70][71], bulk viscosity [69,70,72], thermal conductivity [69,70], and gas-liquid surface tension [73,74]. In particular, many-body interatomic interactions were found to play a significant role in the formation of bulk viscosity in dense argon fluid [72].…”

Bulk viscosity of liquid noble gases

“…133 The Lennard-Jones interaction potential was used, which has demonstrated to resolve such small-scale dynamics adequately and hence successfully describes macroscopic transport in liquid noble gases. [134][135][136][137][138] In the present work, the bulk viscosity's autocorrelation function BA was sampled in the microcanonical (NVE) ensemble, utilizing the fully open source program ms2. 139 The necessary average energies ⟨E⟩ were determined by preceding canonical (NVT) ensemble simulations for the given pair of temperature and density.…”

Ash Fusion Properties from Molecular Dynamics Simulation: Role of the Ratio of Silicon and Aluminum

“…Here, tentative prediction on the shear viscosity of coal ash is carried out by the MD method, and the results are explained from the microscopic view. Shear viscosity was calculated adopting the Green–Kubo formula , where η is the viscosity, V is the volume, k B is the Boltzmann constant, P αβ denotes the off-diagonal stress tensor, and angular brackets represent the ensemble average.…”