  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.
