Kelvin-Helmholtz instability in strongly coupled dusty plasma with rotational shear flows and tracer transport

TL;DR

This study numerically investigates Kelvin-Helmholtz instability in strongly coupled dusty plasmas with rotational shear flows, revealing enhanced mixing and transport behaviors due to vortex and shear wave interactions, and includes tracer particle analysis.

Contribution

It introduces a generalized hydrodynamic model for strongly coupled dusty plasmas with rotational shear flows and incorporates tracer particles to analyze diffusion and mixing.

Findings

KH vortices form at circular interfaces between rotating flows.

Enhanced mixing and transport due to vortex-shear wave interplay.

Preliminary tracer analysis shows clustering and diffusion patterns.

Abstract

Kelvin-Helmholtz (KH) instability plays a significant role in transport and mixing properties of any medium. In this paper, we numerically explore this instability for a two-dimensional strongly coupled dusty plasma with rotational shear flows. We study this medium using generalized hydrodynamic fluid model which treats it as viscoelastic fluid. We consider the specific cases of rotating vorticity with abrupt radial profiles of rotation. In particular: single-circulation, and multi-circulation vorticity shell profiles have been chosen. We observe the KH vortices at each circular interface between two relative rotating flows along with a pair of ingoing and outgoing wavefronts of transverse shear waves. Our studies show that due to the interplay between KH vortices and shear waves in the strongly coupled medium, the mixing and transport behaviour are much better than inviscid hydrodynamic fluids. In interests of substantiating the mixing and transport behaviour, the generalized hydrodynamic fluid model is extended to include the Lagrangian tracer particles. The numerical dispersion of these tracer particles in a flow provides an estimate of the diffusion in such a medium. We present the preliminary observations of tracers distribution (cluster formation) and their diffusion (mean square displacement) across the medium.