Table of Contents
Physics Research International
Volume 2011 (2011), Article ID 782172, 8 pages
http://dx.doi.org/10.1155/2011/782172
Research Article

A Self-Similar Flow behind a Magnetogasdynamic Shock Wave Generated by a Moving Piston in a Gravitating Gas with Variable Density: Isothermal Flow

1Department of Mathematics, National Institute of Technology Raipur, G. E. Road, Raipur 492010, India
2Department of Mathematics, K.S. Saket P.G. College, Faizabad 224001, India

Received 20 April 2011; Accepted 28 July 2011

Academic Editor: Neil Sullivan

Copyright © 2011 G. Nath and A. K. Sinha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The propagation of a cylindrical (or spherical) shock wave in an ideal gas with azimuthal magnetic field and with or without self-gravitational effects is investigated. The shock wave is driven out by a piston moving with time according to power law. The initial density and the initial magnetic field of the ambient medium are assumed to be varying and obeying power laws. Solutions are obtained, when the flow between the shock and the piston is isothermal. The gas is assumed to have infinite electrical conductivity. The shock wave moves with variable velocity, and the total energy of the wave is nonconstant. The effects of variation of the piston velocity exponent (i.e., variation of the initial density exponent), the initial magnetic field exponent, the gravitational parameter, and the Alfven-Mach number on the flow field are obtained. It is investigated that the self-gravitation reduces the effects of the magnetic field. A comparison is also made between gravitating and nongravitating cases.