Experimental Analysis of Reflected Shock Behavior over a Wedge with Suface Roughness. Local Behavior.

Abstract

Detailed experimental analysis has been made on shock reflection over a wedge with surface roughness in a shock tube. The incident shock Mach number M was 1. 43. The experimental parameters were the reflecting wedge angle and the size of gutters. The wave structure is similar amongst model wedges. Detailed measurement into the triple point trajectory shows that it is not a straight line but a slowly varying curve with a kink point where the slope of the tangent to the curve increases discontinuously and that the kink point coincides with the location where the secondary shock, formed by the accumulation of waves reflected from gutters, overtakes the triple point. Three effective values are introduced for experimental analysis of this essentially unsteady phenomenon. Before the kink point the effective angles of incidence and reflection differ greatly from those obtained from the three-shock theory. The angles agree fairly well with the theory beyond this point.