Viscosity calculated in simulations of strongly-coupled dusty plasmas with gas friction

TL;DR

This study uses molecular dynamics simulations to calculate static and wave-number-dependent viscosities in strongly-coupled dusty plasmas, validating methods and the Green-Kubo relation under experimental friction conditions.

Contribution

It introduces and validates a method for calculating wave-number-dependent viscosity and confirms the Green-Kubo relation's applicability in dusty plasma simulations with gas friction.

Findings

Wave-number-dependent viscosity $ ext{eta}(k)$ matches between simulation methods.

Green-Kubo relation accurately measures static viscosity with modest friction.

Method validation enhances understanding of viscosity in dusty plasmas.

Abstract

A two-dimensional strongly-coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity $\eta$ and the wave-number-dependent viscosity $\eta(k)$ are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity $\eta(k)$ is validated by comparing the results of $\eta(k)$ from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity $\eta$ in the presence of a modest level of friction as in dusty plasma experiments.