Özet:

In this paper the stability of the non-uniformly rotating cylindrical plasma in the axial uniform magnetic field with the vertical temperature gradient is investigated. In the approximation of geometrical optics a dispersion equation for small axisymmetric perturbations is obtained with the effects of viscosity, ohmic and heat conductive dissipation taken into account. The stability criteria for azimuthal plasma flows are obtained in the presence of  the vertical temperature gradient and  the constant magnetic field. The Rayleigh-Benard problem for stationary convection in  the non-uniformly rotating layer of the electrically conducting fluid in the axial uniform magnetic field is considered. In the linear theory of stationary convection the critical value of the Rayleigh number  subject to the profile of  the inhomogeneous rotation (Rossby number) is obtained. It is shown that the negative values of the Rossby number  have a destabilizing effect, since the critical Rayleigh number  becomes smaller, than in the case of the uniform rotation , or of the rotation with positive Rossby numbers . To describe the  nonlinear convective phenomena the local Cartesian coordinate system was used, where the inhomogeneous rotation of the fluid layer  was represented as the rotation with a constant angular velocity  and azimuthal shear  with linear dependence on the coordinate. As a result of applying the method of perturbation theory for the small parameter of supercriticality of the stationary Rayleigh number  a nonlinear Ginzburg-Landau equation was obtaned. This equation describes the evolution of  the finite amplitude of perturbations by utilizing the solution of the Ginzburg-Landau equation. It is shown that the weakly nonlinear convection based on the equations of the six-mode Lorentz model transforms into the identical Ginzburg-Landau equation. By utilizing the solution of the Ginzburg-Landau equation, we determined the dynamics of unsteady heat transfer for various profiles of the angular velocity of the rotation of electrically conductive fluid.

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