Finite Larmor radius effect on thermosolutal instability of a compressible Hall plasma in porous medium

1999 ◽  
Vol 6 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Sunil
Keyword(s):  
Porous Medium ◽  
Larmor Radius ◽  
Finite Larmor Radius ◽  
Hall Plasma

Thermal instability of a compressible finite-Larmor-radius Hall plasma in a porous medium

1996 ◽  
Vol 55 (1) ◽  
pp. 35-45 ◽  
Author(s):  
R. C. Sharma ◽  
Sunil
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Thermal Instability ◽  
Hall Current ◽  
Larmor Radius ◽  
Vertical Magnetic Field ◽  
Finite Larmor Radius ◽  
Medium Permeability ◽  
Hall Plasma

The thermal instability of a compressible plasma in a porous medium is considered in the presence of a uniform vertical magnetic field to include the Hall-current and finite-Larmor-radius effects. The system is found to be stable for (cp/g) β < 1, where cp, β and g are the specific heat at constant-pressure, the uniform adverse temperature gradient and the acceleration due to gravity respectively. The uniform vertical magnetic field, Hall-current and finite. Laimor-radius effects introduce oscillatory modes in the system for (cp/g) β ≤ 1, which were non-existent in their absence. The Hall current and finite Larmor radius (FLR) individually have destabilizing and stabilizing effects respectively on the system. In their simultaneous presence there is competition between the destabilizing role of the Hall current and the stabilizing role of the FLR, and each succeeds in stabilizing a certain wavenumber range. In the absence of a magnetic field (and hence the absence of an FLR and Hall current), the destabilizing effect of medium permeability is seen, but in the presence of a magnetic field (and hence the presence of an FLR and Hall current), the medium permeability may have a stabilizing or a destabilizing effect on the thermal instability of the plasma. The effect of compressibility is found to postpone the onset of thermal instability in plasma.

Effects of Finite Larmor Radius and Hall Currents on Thermosolutal Instability of a Partially Ionized Plasma in Porous Medium

1994 ◽  
Vol 49 (3) ◽  
pp. 469-474 ◽  
Author(s):  
Kirti Prakash ◽  
Seema Manchanda
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Wave Number ◽  
Larmor Radius ◽  
Stationary Convection ◽  
Number Range ◽  
Finite Larmor Radius ◽  
Medium Permeability ◽  
Stabilizing Effect ◽  
Partially Ionized

Abstract The effects of finite ion Larmor radius (FLR), collisions and Hall currents on thermosolutal instability of a partially ionized plasma in porous medium in the presence of uniform vertical magnetic field are investigated. It is found that the presence of each magnetic field, FLR, Hall currents and collisions, introduces oscillatory modes which were, otherwise, non-existent. In the case of stationary convection, finite Larmor radius, Hall currents, medium permeability and magnetic field may have stabilizing or destabilizing effects, but for a certain wave number range, FLR, magnetic field and Hall currents have a complete stabilizing effect. The stable solute gradient always has stabilizing effect on the system whereas the collisional effects disappear for the case of stationary convection.

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