A Study of the Complex Flow Features Behind a Diffracted Shock Wave on a Convex Curved Wall

The complex flow features behind a diffracted shock wave on a convex curved wall is investigated using large scale experimentation complemented by numerical computation. The study aimed at explaining the global flow behavior within the perturbed region behind the diffracted shock wave. Experiments were conducted in a purpose built shock tube that is capable of generating a range of incident shock Mach numbers Mn ≤ ۱.۶. Analysis of higher Mach number shocks on different wall geometries were carried out using numerical code that has been validated by earlier authors. Many flow features that were only distinct at high Mach numbers are clearly identified at low Mach numbers in the present investigation. The separation point moves upstream at incident shock Mach number Mn = ۱.۵ but moves downstream at higher Mach numbers and is nearly stationary at Mn = ۱.۶. At incident shock Mach number ۳.۰ the movement of the separation point tends to be independent of the wall curvature as the wall radius approaches infinity. The present investigatio is important in the design of high speed flow devices and in the estimation of flow resistance on supersonic devices and space vehicles.

Keywords:

Compressible flow , Shock wave diffraction , Shear layer , Flow separation