Spiral waves in driven dusty plasma medium: Generalized hydrodynamic fluid description

Abstract

Spiral waves are observed in many natural phenomena. They have been extensively represented by the mathematical FitzHugh-Nagumo (FHN) model [Barkley et al., Phys. Rev. A 42, 2489] of excitable media. In incompressible fluid simulations also excitation of thermal spiral waves have been reported by Li et al. [Phys. of Fluids 22, 011701 (2010)]. In the present manuscript the spatiotemporal development of spiral waves in the context of weak and strong coupling limits have been shown. While the weakly coupled medium has been represented by a simple fluid description, for the strong coupling a generalized visco -elastic fluid description has been employed. The medium has been driven by an external force in the form of a rotating electric field. It is shown that when the amplitude of force is small the density perturbations in the medium are also small. In this case the excitations do not develop as a spiral wave. Only when the amplitude of force is high so as to drive the density perturbations to nonlinear amplitudes does the spiral density wave formation occur. The role of forcing frequency, the effect of strong coupling and sound velocity of medium on the formation and evolution of spiral waves have been investigated in detail.

Spiral waves in driven strongly coupled Yukawa systems

“…In case the radial propagation is too slow the rings diffuse amongst each other and the spiral structure is not so distinctive. The parametric dependence is consistent with the continuum study carried out by Kumar et al [20] wherein the dusty plasma was considered as a visco-elastic fluid.…”

“…For compressible dusty plasma medium, in both weak and strongly coupled regime depicted by fluid and generalized hydrodynamic visco-elastic model, respectively, the spiral density waves have been shown to propagate under the influence of external forcing [20]. The dusty plasma is essentially made up of discrete charged dust particles which are of macroscopic size compared to the lighter electron and ion species present in the medium.…”

Molecular dynamics study of crystal formation and structural phase transition in Yukawa system for dusty plasma medium

“…Dusty plasma has proved to be an interesting ideal model for studying various natural phenomena concerning collective structures 1-11 , linear and nonlinear waves [12][13][14][15][16][17][18][19] , instabilities [20][21][22][23][24] . It also has relevance in the context of certain astrophysical phenomena [25][26][27] where its implications are being studied.…”

DPEx-II: A New Dusty Plasma Device Capable of Producing Large Sized DC Coulomb Crystals

“…Excitations of spiral and circular wave and their propagation have been spotted in varieties of physical system ranging from living cells to astrophysical objects. The emergence of these waves often been witnessed as an interplay between local inhibitor (prey) and exciter (predator) mechanism in the non-equilibrium systems through computer simulation 56,57 . The self-organization of excitations in the medium gives rise to the pattern of spiral wave 58 .…”