Diffraction of Oblique Shock by Yawed Wedges

Abstract

Chester (1954) considered the problem of reflection and diffraction of plane shock wave interacted by yawed wedges which was the extension of the Lighthill’s (1949) problem of diffraction of a normal shock wave past a small bend. The results presented in this chapter are the generalisation of the results given in chapter IV to the case of yawed wedges (Chopra & Srivastava(1972), Chopra(1972)). More specifically this attempt is concerned with the study of interaction of an oblique shock configuration(consisting of incident and reflected shock) with a yawed wedge i.e. shock line (intersection of incident and reflected shock) makes some non zero angle with the leading edge of the wedge. The theoretical investigation of the flow field produced after the interaction is difficult not only because of the non- linear nature of the problem, but also because of the fact that the diffraction of the reflected shock will result in variations in entropy of the fluid and a loss of irrotational character of the motion. On the assumption that the wedge produces only small perturbations in the uniform flow, the entropy variations, though not negligible can, however, be suppressed from the equations governing the flow by basing the analysis on pressure perturbation; in any case the pressure is the most interesting variable.