An experimental investigation of the cold flowfield in a model scramjet combustor

Abstract

In order to obtain the cold flow structures inside a model scramjet combustor, direct-connected experiments have been conducted on the inlet Mach number of 2.0. The length to height ratio of the isolator is 6 and 8. The static pressure along the wall is measured with varied back pressure. The Schlieren technique is employed for visualizing the typical shock train structures in the model. The results indicate that the flowfield in the scramjet combustor is rather complicated because of shock wave/boundary layer interaction. The first shock of the normal shock train is bifurcated at the foot, while the subsequent shocks are seen to be of nearly normal shock. Each successive shock is weaker. The shock train moves towards the isolator entrance as back pressure increases. The position of the leading edge of shock train is sensitive to the pressure variation. The isolator of L_iso/ h=8 can sustain pressure rise better than L_iso/ h=6.