Energy Transport in a Shear Flow of Particles in a 2D Dusty Plasma

TL;DR

This study investigates energy transport in a 2D dusty plasma shear flow by analyzing particle velocity data to determine viscosity and thermal conductivity, providing spatially-resolved insights into viscous heating and thermal conduction.

Contribution

It introduces a method to simultaneously measure viscosity and thermal conductivity in a dusty plasma shear flow using continuum data derived from particle tracking.

Findings

Values for viscosity and thermal conductivity were obtained from the experiment.

Spatial profiles of viscous heating and thermal conduction were characterized.

The energy and momentum equations were validated through spatially-resolved analysis.

Abstract

A shear flow of particles in a laser-driven two-dimensional (2D) dusty plasma are observed in a further study of viscous heating and thermal conduction. Video imaging and particle tracking yields particle velocity data, which we convert into continuum data, presented as three spatial profiles: mean particle velocity (i.e., flow velocity), mean-square particle velocity, and mean-square fluctuations of particle velocity. These profiles and their derivatives allow a spatially-resolved determination of each term in the energy and momentum continuity equations, which we use for two purposes. First, by balancing these terms so that their sum (i.e., residual) is minimized while varying viscosity $\eta$ and thermal conductivity $\kappa$ as free parameters, we simultaneously obtain values for $\eta$ and $\kappa$ in the same experiment. Second, by comparing the viscous heating and thermal conduction terms, we obtain a spatially-resolved characterization of the viscous heating.