Solution numérique de l'équation des ondes d'Alfven avec un terme de dissipation par résistance
This paper introduces an isoparametric analysis to solve the Vlasov equation with a semi-Lagrangian scheme. A Vlasov-Poisson problem modeling a heavy ion beam in an axisymmetric configuration is considered. Numerical experiments are conducted on computational meshes targeting different geometries. The impact of the computational grid on the accuracy and the computational cost are shown. The use of analytical mapping or Bézier patches does not induce...
We consider plasma tearing mode instabilities when the resistivity depends on a flux function (ψ), for the plane slab model. This problem, represented by the MHD equations, is studied as a bifurcation problem. For so doing, it is written in the form (I(.)-T(S,.)) = 0, where T(S,.) is a compact operator in a suitable space and S is the bifurcation parameter. In this work, the resistivity is not assumed to be a given quantity (as usually done in previous papers, see [1,2,5,7,8,9,10], but it depends...
In questo lavoro si studia la instabilità gravitazionale di un fluido comprimibile, elettroconduttore, descritto dalle equazioni della magnetofluidodinamica in presenza delle correnti di Hall e di ion slip. Si determina la condizione per la instabilità relativa ad una classe di perturbazioni assialsimmetriche.
In this paper we extend to Plasma Mechanics the study of the hydrodynamic steady motions in which the streamlines are circular helixes. The plasma is described by the magnetofïuiddynamic equations with the Hall effect. Velocity and magnetic fields (and, in correspondence, the pressure field) that make such motions possible are determined. So a class of exact solutions of the magnetofïuiddynamic equations with the Hall effect is pointed out.
This paper studies the magnetodynamic equilibrium of a radiative, infinitely conducting plasma, undergoing both a rotation motion around a symmetry axis and a motion in the meridian plans. It is assumed that on plasma acts its own gravitation. In the first nota the plasma is considered incompressible; for such a plasma the approximation of a perfect gas is valid.
This paper studies the magnetodynamic equilibrium of a radiative, infinitely conducting plasma, undergoing both a rotation motion around a symmetry axis and a motion in the meridian plans. It is assumed that on plasma acts its own gravitation. In the second note the plasma is supposed to be polytropic and compressible. The stability criterion of such a splasma is also obtained.