共查询到20条相似文献，搜索用时 31 毫秒
1.
The thermal-convective instability of a composite stellar atmosphere is considered in the presence of rotation, variable horizontal magnetic field, and collisional effects. The criteria for monotonic instability are obtained which generalize the criterion derived for thermal-convective instability in the absence of above effects. 相似文献
2.
K. C. Sharma 《Astrophysics and Space Science》1986,125(2):299-304
The problem of thermal-convective instability of a hydromagnetic composite plasma in a stellar atmosphere has been studied with Hall effects. The criterion for monotonic instability has been found to be unchanged by the presence of Hall effects. 相似文献
3.
The thermal-convective instability of a composite rotating stellar atmosphere in the presence of a variable horizontal magnetic field is considered to include, separately, the effects of medium permeability and solute gradient. The criteria for monotonic instability in each case have been obtained which generalize the Defouw's criterion derived for thermal-convective instability in the absence of above effects. 相似文献
4.
The thermosolutal-convective instability of a stellar atomsphere is studied in the presence of suspended particles. The criteria
for monotonic instability are derived and are found to hold good also in the presence of uniform rotation and uniform magnetic
field on the thermosolutal-convective instability. The thermosolutal-convective instability of a stellar atmosphere is also
studied in the presence of suspended particles and radiative transfer effects and the criteria for monotonic instability are
obtained in terms of source function. 相似文献
5.
Thermosolutal-convective instability of a composite plasma in a stellar atmosphere is considered to include the effects, separately, due to finite Larmor radius (FLR) and Hall currents in the presence of a uniform horizontal magnetic field. The sufficient conditions for the existence of monotonic instability are derived and are found to hold good both in the presence, separately, of FLR and Hall current effects. 相似文献
6.
Thermosolutal-convective instability of a stellar atmosphere is considered. The criteria for monotonic instability are derived. The effects of a variable horizontal magnetic field and the simultaneous presence of a uniform rotation and a uniform horizontal magnetic field have been considered on the thermosolutal-convective instability. The criteria derived for monotonic instability are found to hold good in the presence of a variable horizontal magnetic field as well as in the presence of a uniform rotation and a uniform horizontal magnetic field. 相似文献
7.
K. C. Sharma 《Astrophysics and Space Science》1987,137(2):297-302
Thermal-convective instability of a composite plasma in a stellar atmosphere, when the effects of a uniform rotation and a uniform magnetic field are included simultaneously, is discussed. It is found that the criterion for monotonic instability is the same as in the absence or presence (separately) of these two effects. 相似文献
8.
Thermosolutal-convective instability of a stellar atmosphere in the presence of a stable solute gradient is considered to include the effects, separately, due to finite Larmor radius (FLR) and Hall currents in the presence of a uniform horizontal magnetic field. The criteria derived for monotonic instability are found to hold true in the presence of FLR and Hall effects. 相似文献
9.
On thermal-convective instability in a stellar atmosphere with finite Larmor radius and Hall effects
The thermal-convective instability of a stellar atmosphere is considered to include rotation, finite Larmor radius and Hall effects in the presence of a uniform vertical magnetic field. The criterion for monotonic instability is found to be the same even if the above effects are included. 相似文献
10.
K. C. Sharma 《Journal of Astrophysics and Astronomy》1988,9(1):1-5
Thermal-convective instability of a hydromagnetic, composite, rotating, inviscid and infinitely conducting plasma in a stellar
atmosphere has been studied in the presence of finite Larmor radius. It is found that the criterion for monotonic instability
holds good in the presence of the effects due to rotation and finite Larmor radius. 相似文献
11.
R. C. Sharma 《Astrophysics and Space Science》1974,29(1):L1-L4
The gravitational instability of an infinite homogeneous self-gravitating rotating plasma in the presence of a uniform vertical magnetic field has been studied to include the FLR effects. It has been found that the Jeans' criterion of instability remains unaffected even if rotation and FLR effects are included. The effect of rotation is to decrease the Larmor radius by an amount-depending upon the wavenumber of perturbation. The particular cases of the effect of FLR and rotation on the waves propagated along and perpendicular to the magnetic field have been discussed. 相似文献
12.
The thermosolutal instability of a partially-ionized plasma in the presence of a horizontal magnetic field is considered to include the frictional effect of collisions of ionized with neutrals. The sufficient conditions for non-existence of overstability are derived. The solute gradient and magnetic field introduce oscillatory modes in thermosolutal convection which were non-existent in their absence. The magnetic field and stable solute gradient are found to have stabilizing effects whereas collisional effect of ionized with neutrals is found to have destabilizing effect on thermosolutal instability of a partially ionized plasma. 相似文献
13.
The gravitational instability of an infinite homogeneous self-gravitating plasma through porous medium is considered to include, separately, the effects due to rotation and collisions between ionized and neutral components. The dispersion relations are obtained in both cases. It is found that the gravitational instability of a composite and rotating plasma in the presence of a variable horizontal magnetic field through porous medium is determined by the Jeans's criterion. 相似文献
14.
Thermal instability of a compressible rotating plasma in the presence of a uniform vertical magnetic field is studied to include the effects of finiteness of the ion-Larmor radius. When the instability sets in as stationary convection, the compressibility is found to have stabilizing effect. It is found that finite Larmor radius effects are always stabilizing forx greater than two and forx less than two they have a destabilizing influence in the presence of rotation. The stabilizing effect of coriolis force is observed and for the case of no rotation, finite Larmor radius effects are always stabilizing. The sufficient conditions for the nonexistence of overstability are investigated. 相似文献
15.
Bhimsen K. Shivamoggi 《Astrophysics and Space Science》1981,79(1):3-9
A study of the Rayleigh instability of a compressible plasma of density stratified in horizontal planes and subjected to a vertical magnetic field is made. The special case of a plane interface separating two superposed uniform plasmas of different densities and speeds of sound is treated as an example to illustrate the compressibility effects on the hydromagnetic Rayleigh instability. It is found that the hydromagneticcompressibility effects act toward reducing the growth rate in a hydrodynamically unstable situation. 相似文献
16.
Thermal-convective instability of a hydromagnetic, composite, rotating, inviscid, and infinitely conducting plasma in a stellar atmosphere has been studied in the presence of Hall currents. It is found that the criterion for monotonic instability holds good in the presence of the effects due to rotation and Hall currents. 相似文献
17.
Bhimsen K. Shivamoggi 《Astrophysics and Space Science》1982,86(2):371-376
The gravitational instability of an infinite cylinder of a self-gravitating, perfectly-conducting, compressible fluid subjected to a uniform axial magnetic field is investigated. A generalised dispersion relation describing the stability characteristics of the configuration is given. The gravitational instability of the cylinder is found to be worsened in the presence of the compressibility effects in the fluid. 相似文献
18.
Thermosolutal instability of a rotating plasma with finite Larmor radius and Hall effects is studied. When the instability sets in as stationary convection, the Hall currents and the stable solute gradient are found to have destabilizing and stabilizing effects, respectively. For the case of no rotation, finite Larmor radius effects are always stabilizing forx greater than two and forx less than its critical valueN
cr. In the limit of vanishing Hall current, the stabilizing effect of Coriolis force is observed. The question of onset of instability as overstability is also discussed. 相似文献
19.
K. C. Sharma 《Astrophysics and Space Science》1982,85(1-2):263-269
The gravitational instability of an infinite homogeneous and infinitely conducting selfgravitating gas particle medium in the presence of suspended particles of a Hall plasma is considered. The particular cases of the effects of Hall currents and suspended particles on the waves propagated along and perpendicular to magnetic field have been discussed. Jeans's criterion determines the gravitational instability. 相似文献
20.
The thermosolutal instability of a partially-ionized plasma in porous medium is considered in the presence of a uniform vertical magnetic field to include the effects of collisions and Hall currents. For the case of stationary convection, Hall currents and medium permeability have destabilizing effects whereas the stable solute gradient has stabilizing effect on the system. The collisional effects disappear for stationary convection. The sufficient conditions for the existence of overstability are obtained. 相似文献