Combustion tests of a staged supersonic combustor with a strut

To avoid combustor-inlet interaction, a staged supersonic combustor with a strut for the first-stage injection and second-stage wall injectors at its divergent section was introduced to increase the pressure in the divergent section under the limitation of the peak pressure at its minimum cross-sect ional area section. The combustor was tested experimentally in a direct-con nect wind-tunnel facility with a combustion heater that supplied Mach 2.5 a irflow with a total temperature of 1500 K. With the staged injections, the pressure rise due to the second-stage combustion was isolated from that due to the first-stage combustion. Fuel with an equivalence ratio more than un ity, twice that of the allowable flow rate with the first-stage injection a lone, could be injected without the interaction, and the maximum thrust inc rement was augmented by 100%. The effects of the second-stage injector plac ements were also examined, and it was found that the second-stage injection farther upstream resulted in the interaction, but that the injection furth er downstream resulted in low thrust due to low combustion efficiency.