The investigation of magnetohydrodynamics shock waves refractions at an oblique density interfaces in the plasma physics

When a shock front hits to the density interface (a junction of two fluid of different densities), it both reflects and refracts similar to the behaviours of light beams in optics. Together with incident shock front, the structure appears known as the triple wave in the literature. Magnetic field has an important role for the dynamics of fluids in the plasma physics. Analysing processes get hard when the magnetic field is taken into consideration. Similar to other magnetohydrodynamics waves the reflected and refracted fronts have fast-middle-slows components, and the structure appears known as septuple-wave. The middle and slow fronts are were close therefore they can be accepted as one front and the quintuple wave structure occurs. In this present thesis, the flow of plasma was studied in the quintuple wave structure formed by density interfaces for weak shocks (i.e. r=1.1). In addition, the hydrodynamics flows having same flow characteristic to MHD is also studied.From the investigation of magnetized case, it is found that some instabilities known as interface instabilities in the fluid literature (such as, Ritchmer-Meshkov, Rayleigh-Taylorv and Kelvin-Helmholtz) can arise in the region between reflected and transmitted shock fronts. Moreover, it is also estimated that, there may be turbulent mixing of the density interface for the progressing phases of instabilities.