Reflection and Diffraction of Shock Waves and Shock-Wave Configurations

Abstract

There are two phenomena, which can result from interaction of a shock wave (SW) with a solid surface. A SWreflects off a surface if the angle of incidence is less than 90°. If the angle of incidence is more than 90°, the shock wave diffracts over a surface. At once it is necessary to note that the diffraction phenomenon does not exist in steady flows. Moreover, for steady flows the term “head-on reflection of a SW” loses any meaning and there is no possibility to propose the elementary 5-shock model of the irregular intersection of two arbitrary SWs [1]. These facts reveal the principal differences between the processes of shock wave interaction in the steady and unsteady flows. In the case of shock wave reflection in the steady flows, we deal with a result of reflection in a shock-wave configuration form. Only two configurations — regular 2-shock (RR) and Mach 3-shock (MR) structures — are observed in steady flows and not any parameter of the configuration, including geometrical one, does not change in time. Von Neumann [2] proposed the analytical models of two. and three-shock waves configurations and formulated the local theories, which are valid for describing the flow field in the small vicinity of the intersection point regardless of the conditions of configurations origins.