Experimental Study of Combustor-Isolator Interactions in a Dual-Combustion Ramjet

Abstract

Combustor-isolator interactions are investigated in a direct-connect dual-combustion ramjet experiment. The test apparatus contained an annular isolator, a constant cross-sectional area cylindrical supersonic combustor, and a subsonic-burning gas generator. The gas generator, in which a liquid hydrocarbon fuel was injected, produced a fuelrich hot-gas mixture that is mixed with the annular supersonic airflow in the supersonic combustor. Aprecombustion compression field was generated, both in the isolator and the combustor, by the heat release. The annular isolator entrance Mach number was varied as 1.78, 1.98, and 2.23. The wall static pressure distributions measured in the isolator and the combustor are presented and analyzed to determine the precombustion shock-train length. The new correlating equations and the corresponding theoretical model that can predict the precombustion shock-train length and the wall pressure distribution are derived therefrom.