Analytic structure of a drag-driven confined dust vortex flow in plasma

Abstract

Flow structure of a dust medium electrostatically suspended and confined in a plasma presents a unique setup where the spatial scale of a volumetric drive by the plasma flow might exceed that of the boundaries confining the dust. By means of a formal implementation of a two-dimensional hydrodynamic model to a confined dust flow and its analytic curvilinear solutions, it is shown that the eigenmode spectrum of the dust vortex flow can lose correlations with the driving field even at the low dust Reynolds numbers as a result of strong shear and finer scales introduced in the equilibrium dust vorticity spectrum by the boundaries. While the boundary effects can replace the desired turbulent processes unavailable in this regime, the shear observable in most of the dust vortex flows is identified to have a definite exponent of dependence on the dust viscosity over a substantially large range of the latter. These results and scalings allow quantification of the notion of dusty plasma medium as a paradigm for a wide range of natural flow processes having scales inaccessible to ordinary laboratory experiments.

Dynamic Behavior of Dust Particles in Plasmas

“…Our results have inspired other researchers in wider fields beyond plasma physics [64][65][66][67][68][69][70][71][72][73][74][75][76]. The followings are examples.…”

“…Gibson et al gave an improved understanding of magnetized electron behavior in a dipole magnetic field [67]. Laishram et al investigated the dust vortex formation in a plasma [68].…”

Overestimation of Viscosity by the Green-Kubo Method in a Dusty Plasma Experiment

“…As it does in fluids, viscosity in plasmas affects instabilities [10], waves [11][12][13], vortices [14], and heating [15]. Despite these similarities, plasmas have unusual viscosity properties because the underlying Coulomb forces have a long range, unlike the short-range interactions typical of liquids and gases.…”

A dusty plasma model for vortex structure in Jupiter atmosphere

“…Considering the resemblance of dynamics of GRS and White Ovals to that of the bounded dust cloud in the streaming plasma which follows the incompressible and isothermal conditions, the dynamics of both systems in a 2D XY -plane, though vastly different in appearance, may be modeled using the modified Navier-Stokes equations in terms of the stream function ψẑ and the flow vorticity ωẑ as follows [20][21][22], Here, ẑ is unit vector normal to the XY -plane, u is the dust flow velocity, ω s is the collective vorticity source from the sheared streaming background plasma. And the dynamic regime is determined by system parameters µ, ξ, and ν [23][24][25]. For a laboratory glow discharge argon plasma, a typical set of parameters are n ≃ 10 9 cm −3 , T e ≃ 3eV , T i ≃ 1eV , with system size L x ∼ 10 cm, and ions shear flow strength U 0 equivalent to the fraction of ion acoustic velocity c s = T e /m i , the value of parameters are ξ ∼ 10 [20,25,26].…”