Shear Thinning in Lennard-Jones Fluids by Stochastic Dissipative Molecular Dynamics Simulation

TL;DR

This paper uses stochastic dissipative molecular dynamics simulations to study shear thinning in Lennard-Jones fluids, revealing how shear viscosity decreases with shear rate and system size effects at high shear rates.

Contribution

It introduces a generic constraint in SDMD that reduces sensitivity to thermostat parameters and explores shear viscosity behavior at various shear rates and system sizes.

Findings

Shear viscosity decreases with increasing shear rate.

System size influences shear viscosity at high shear rates.

Shear thinning behavior observed in Lennard-Jones fluids.

Abstract

The shear viscosity of a Lennard-Jones fluid is obtained by stochastic dissipative molecular dynamics (SDMD) simulations. A generic constraint to the equations of motion is given that reduces the sensitivity of the shear viscosity to the value of the the fluctuation-dissipation or thermostat parameter. At high shear rates the shear viscosity becomes dependent on the size of the system, and corrections to the equipartition kinetic temperature arise. At constant kinetic temperature the shear viscosity is shown to decrease with increasing shear rate.