Rayleigh-Taylor Instability in Magnetized Plasma

Rayleigh–Taylor (RT) and buoyancy-driven (BD) instabilities are driven by gravity in a fluid system with inhomogeneous density. The paper investigates these instabilities for a strongly coupled dusty plasma medium. This medium has been represented here in the framework of the generalized hydrodynamics (GHD) fluid model which treats it as a viscoelastic medium. The incompressible limit of the GHD model is considered here. The RT instability is explored both for gradual and sharp density gradients stratified against gravity. The BD instability is discussed by studying the evolution of a rising bubble (a localized low-density region) and a falling droplet (a localized high-density region) in the presence of gravity. Since both the rising bubble and falling droplet have symmetry in spatial distribution, we observe that a falling droplet process is equivalent to a rising bubble. We also find that both the gravity-driven instabilities get suppressed with increasing coupling strength of the medium. These observations have been illustrated analytically as well as by carrying out two-dimensional nonlinear simulations. Part 2 of this paper is planned to extend the present study of the individual evolution of a bubble and a droplet to their combined evolution in order to understand the interaction between them.

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“…2006; Sen, Fukuyama & Honary 2010; Haines et al. 2014; Hoshoudy 2014; Kessler, Dahlburg & Ganguli 2014; Weber et al. 2014; Khiar et al.…”

Section: Introductionmentioning

confidence: 99%

A numerical study of gravity-driven instability in strongly coupled dusty plasma. Part 1. Rayleigh–Taylor instability and buoyancy-driven instability

Dharodi

Das

2021

J. Plasma Phys.

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“…The gravitational instability of a rotating Walters B' viscoelastic partially ionized plasma permeated by an oblique magnetic field in the presence of the effects of Hall currents, electrical resistivity and ion viscosity has been considered by El-Sayed and Mohamed [12]. Hoshoudy [13], has investigated the Rayleigh-Taylor instability in stratified plasma in the presence of combined effect of horizontal and vertical magnetic field. Sharma, et al [14], have investigated the effect of surface tension on hydromagnetic Rayleigh-Taylor instability of two incompressible superimposed fluids in a medium with suspended dust particles in a uniform horizontal magnetic field.…”

Section: Introductionmentioning

confidence: 99%

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2020

AJAMS

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Rayleigh-Taylor instability of a composite medium with variable density and viscosity is considered by taking into account the frictional effect of collisions of ionized with neutral atoms in the presence of a variable horizontal magnetic field. The criteria determining stability and instability are independent of the effects of viscosity and collisional effects. The magnetic field stabilizes the system which is otherwise unstable in the absence of the magnetic field. The viscosity of the medium has stabilizing as well as destabilizing effect on the growth rates. The collisional frequency has stabilizing effect on the growth rates, but has also destabilizing effect in some region.

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“…Furthermore, in the context of plasma medium the charged species respond to electromagnetic forces and various scenarios arise where an inverse stratification against a force (and/or a pseudo force due to the choice of the frame) leads to this instability. Studies for different types of plasmas under various conditions have been carried out [10][11][12][13][14][15][16][17][18][19][20] . This instability has been observed in diverse situations such as a supernova explosion 21,22 , geophysics 23 , astrophysics 24,25 , atmospheric physics 26 , liquid atomization 27,28 , fusion physics [29][30][31][32] , oceanography 33 , turbulent mixing [34][35][36] , etc.…”

Section: Introductionmentioning

confidence: 99%

A numerical study of gravity driven instability in strongly coupled dusty plasmas.Part I: Rayleigh-Taylor instability and Buoyancy-driven instability

Dharodi,

Das

2020

Preprint

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Rayleigh-Taylor and Buoyancy-driven instabilities are very common instabilities for an inhomogeneous medium. We examine here how these instabilities grow for incompressible viscoelastic fluids like a strongly coupled dusty plasma by using incompressible generalized hydrodynamic (i-GHD) fluid model. Since the dust particles are pretty massive, the gravitational attraction of earth has a significant role in its dynamics. In this paper the acceleration due to gravity g and the role of strong coupling in the context of gravitationally stratified dusty plasma fluid have been considered. We find that the appearance of elasticity speed up the growth of viscoelastic RT instability by reducing the effect of viscosity at timescales shorter than the Maxwell relaxation time τ m . The buoyancy driven situation with spatially localized (in both dimensions) of low/high density regions placed in a background medium has also been evolved in the presence of gravity. Our studies show that both the instabilities get suppressed with increasing coupling strength of the medium. This suppression has been illustrated analytically as well as by carrying out a two-dimensional fully nonlinear simulation.

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Rayleigh-Taylor Instability in Magnetized Plasma

Cited by 7 publications

References 21 publications

A numerical study of gravity-driven instability in strongly coupled dusty plasma. Part 1. Rayleigh–Taylor instability and buoyancy-driven instability

A numerical study of gravity-driven instability in strongly coupled dusty plasma. Part 1. Rayleigh–Taylor instability and buoyancy-driven instability

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A numerical study of gravity driven instability in strongly coupled dusty plasmas.Part I: Rayleigh-Taylor instability and Buoyancy-driven instability

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