Longitudinal viscosity of 2D Yukawa liquids

TL;DR

This study uses molecular dynamics simulations to measure the longitudinal viscosity of a 2D Yukawa liquid, revealing that it closely matches shear viscosity and that bulk viscosity is negligible, providing insights into dusty plasma behavior.

Contribution

First direct computation of longitudinal viscosity in a 2D Yukawa liquid using Green-Kubo and molecular dynamics, showing its relation to shear viscosity and negligible bulk viscosity.

Findings

Longitudinal and shear viscosities are nearly equal across temperature range.

Bulk viscosity is negligible or not meaningful in 2D Yukawa liquids.

Results enhance understanding of transport properties in dusty plasma models.

Abstract

The longitudinal viscosity $\eta_l$ is obtained for a two-dimensional (2D) liquid using a Green-Kubo method with a molecular dynamics simulation. The interparticle potential used has the Debye-H\"{u}ckel or Yukawa form, which models a 2D dusty plasma. The longitudinal $\eta_l$ and shear $\eta_s$ viscosities are found to have values that match very closely, with only negligible differences for the entire range of temperatures that is considered. The bulk viscosity $\eta_b$ is determined to be either negligibly small or not a meaningful transport coefficient, for a 2D Yukawa liquid.