Experimental study of shock wave reflection in a narrow channel

Shock wave reflection at corners in a channel was examined in a shock tube using a mixture of CO2, N and air as the driven gases. Shock speeds ranging from Mach 2.5-4 were employed and studied with Schlieren photography and piezoelectric pressure transducers at the wall. Single and multiple wedges introduced into the channel had cross-sections that could be varied to be equal to or less than the height of bifurcation zone of the reflected shock waves. The configuration caused a secondary shock to form and follow closely behind the reflected shock. Edges in the channel flow retarded boundary layer separation. The size of the bifurcation region controlled the pressure distribution at the wall. Finally, the pressure at the point of boundary layer separation was greater than the stagnation pressure by a factor of 50 percent, in contrast to predictions using the model proposed by Mark (1957).