Diffraction of a Plane Shock Wave Around a Corner

Abstract

Diffraction of a plane shock wave around a sharp convex 90°corner was observed in a shock tube flow with the various shock Mach numbers from 2.8 to 1.5. The shock wave shape observed showed quantitative difference from the theoretical predictions, which are derived from the one-dimensional flow theory and the ray-shock theory. Considering the possible cause of this discrepancy, it is suggested, the shear stress due to turbulent-like mixing between the ray tubes immediately behind the shock front may play an important role in this phehomenon. On the basis of the concept of the turbulent mixing length, a generalized theory, which includes this shear effect, is proposed and a linearized solution of this equation is obtained. The predicted results show good agreement with the experimental data.