Effects of incoming flow total temperature on mode transition boundary in dual mode scramjet combustor

To estimate the effects of incoming flow total temperatures on mode transition boundary in a kerosene-fueled dual mode combustor, an test study was conducted using a direct-connected methane combustion heating test facility. The values of incoming flow total pressure at the isolator inlet should be kept at 1.05 MPa, the Mach number was about 2.0, the incoming flow total temperatures were 885, 1 085, 1 285 K, respectively. Combustor wall pressures were measured by pressure sensors; the mode of combustion was identified by calculating the Mach number at the isolator exit using a one-dimensional model. Test results indicated that, the locations of the combustor peak wall pressure were the same at different incoming flow total temperatures; there was a one-to-one relationship between the combustor peak pressure value, isolator near wall pressure distribution and shock train leading edge location; with the increase of incoming flow total temperature, the equivalence ratio of mode transition from supersonic to subsonic combustion rose up; under the same kerosene equivalence ratio, as the incoming flow total temperature increased, the combustor wall pressure dropped, the length of shock train got shorter.