MHD effects driven by the hypersonic motion of a cylindrical body through a planetary magnetosphere with parallel orientation of the cylinder generator and the magnetic field (Q1577584)

The authors study magnetohydrodynamic effects connected with the motion of an elongated body (a meteoroid) through atmospheres of planets that have their own magnetic field (typical conditions of collision of Shoemaker-Levy 9 comet with the atmosphere of Jupiter are taken). The authors analyse the flow of compressible conducting ideal gas in the planet atmosphere in the presence of magnetic field. It is assumed that the axis of the meteoroid is parallel to the planet's magnetic field and to the gas velocity. The resulting system of equations describing the two-dimensional MHD flow is solved numerically for arbitrary magnetic Reynolds numbers and magnetic pressure parameters, in the Cartesian coordinate system moving with the meteoroid. The detailed calculations are performed and presented in 7 figures. It is shown that the main difference between the results of calculations for dense and for rarefied planet atmospheric layers is due to different MHD interactions of conducting gas flows with the magnetic field of the planet. For dense atmospheric layers the magnetic pressure parameter is small, the magnetohydrodynamic interaction is negligible, and the flow remains almost undisturbed. But for the flow in rarefied atmospheric layers, the magnetohydrodynamic interaction is strong, and two maxima of magnetic field are formed in the shock-compressed zone ahead of the meteoroid.