Pseudo-Shock Waves in a Divergent Channel

Abstract

Pseudo-shock waves in a divergent channel were optically observed by a schlieren method, and the lengths of the pseudo-shock region as well as the static pressure distributions were obtained from pressure measurements. The dimensionless length of pseudo-shock in the divergent channel divided by the mean equivalent diameter before and behind the shock is nearly equal to that in a constant area duct. The static pressure ratio and Mach number across the pseudo-shock in the divergent channel were compared with those in a constant area duct, and the effect of the divergence on the characteristics of the pseudo-shocks was discussed. Assuming a one-dimensional flow and using the experimental pressure distributions in the pseudo-shock region, the flow variables such as the static and stagnation pressures across the pseudo-shock in the divergent channel were calculated. The calculated results agree well with the experimental values.