We study a strong spherical expanding shock wave interacting with the finite-gradient interface between neutral cold gas and weakly ionized plasma. We want to see how the interaction with the interface can alter the shock structure compared to the case of its free propagation through the media with the exponentially varying density. From our comparative calculations based on the 2D model, we found substantial difference in the shock structure including strong deformation of the shock front followed with its gradual flattening and the redirection in its propagation. There are a number of factors that can be used to control this phenomenon in order to strengthen or lessen the effect. The calculations can be made on any scale, limited with the requirement for the shock wave to be strong. The study points at the possibility in certain applications to avoid the shock wave with its redirection rather than attenuation. The results can be applicable to optimization of the energy deposition into the supersonic flux, the drag reduction in hypersonic flight, in the detonation theory, and combustion through the control of the ignition conditions, and for environmental improvements through sonic boom reduction. Cartesian coordinates were used in order to visualize the phenomenon. (C) 2014 AIP Publishing LLC.
