Experimental investigation of effects of dual-cavity configuration on ignition and flame stabilization in a kerosene-fueled supersonic combustor

The effects of two kinds of dual-cavity configuration on ignition and flame stabilization in a high Mach number (Ma) kerosene-fueled scramjet were experimentally investigated in this study. To better understand the combustion characteristics, flow structure and flame development were studied by schlieren photography, flame self-illumination photography, and wall-pressure measurement. Results were obtained with an isolator inlet Ma 3.0, total pressure 2.9 MPa, and total temperature 1900 K, which correspond to a flight Ma ( Ma f) 8.0 condition. The symmetrical dual-cavity configuration did not achieve kerosene auto-ignition, while the staggered dual-cavity configuration did achieve kerosene auto-ignition because shock waves in the staggered dual-cavity scramjet were much more complex than in the symmetrical dual-cavity scramjet downstream of the cavity. In the staggered dual-cavity scramjet, flame stabilization was achieved after successful ignition by a lower equivalence ratio (ER) of kerosene, but when the ER of kerosene was increased to 0.8, flame stabilization was not achieved and the flow structure oscillated quasi-periodically.