Effect of the Radial Density Gradient on Nonlinear Magnetic Hydrodynamic Phenomena in Rotating Plasma

The MHD characteristics of the plasma boundary layer near an extended dielectric disc rotating with a constant angular velocity in an external axial magnetic field are calculated. It is assumed that the conducting medium above the disc rotates at an angular velocity that differs from that of the disc. The analysis is carried out in the isothermal approximation taking into account a significant radial redistribution of the gas density and neglecting the Hall effects. The calculation is carried out by the Slezkin-Targ method using a self-similar transformation with a power-law change in the density of the medium with the radial coordinate. The dependence of the boundary layer thickness xi(1) and radial flow parameter A on the ratio of the angular velocities of rotation of the medium m and the compression degree p is studied. It is shown that an increase in the radial density gradient should lead to a noticeable increase in the moment of azimuthal friction forces in the boundary layer. The dependence of the axial inflow to the disc on the external magnetic field is studied.