Gravitational instability of a composite and rotating plasma in the presence of a variable magnetic field through a porous medium

1992 ◽  
Vol 187 (1) ◽  
pp. 105-111 ◽  
Author(s):  
R. C. Sharma ◽  
A. Rajput
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Gravitational Instability ◽  
Variable Magnetic Field

Rayleigh-Taylor Instability of a Partially Ionized Plasma in a Porous Medium in Presence of a Variable Magnetic Field

1992 ◽  
Vol 47 (12) ◽  
pp. 1227-1231
Author(s):  
R. C. Sharma ◽  
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Variable Magnetic Field ◽  
Taylor Instability ◽  
Wave Number ◽  
Medium Permeability ◽  
Wave Numbers ◽  
Rayleigh Taylor Instability ◽  
Partially Ionized ◽  
The Magnetic Field

Abstract The Rayleigh-Taylor instability of a partially ionized plasma in a porous medium is considered in the presence of a variable magnetic field perpendicular to gravity. The cases of two uniform partially ionized plasmas separated by a horizontal boundary and exponentially varying density, viscosity, magnetic field and neutral particle number density are considered. In each case, the magnetic field succeeds in stabilizing waves in a certain wave-number range which were unstable in the absence of the magnetic field, whereas the system is found to be stable for potentially stable configuration/stable stratifications. The growth rates both increase (for certain wave numbers) and decrease (for different wave numbers) with the increase in kinematic viscosity, medium permeability and collisional frequency. The medium permeability and collisions do not have any qualitative effect on the nature of stability or instability.

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