摘要 : The fuel atomization and ignition characteristics of an afterburner under subatmospheric pressure are important foundations for expanding the operating range of the afterburner at high flight altitudes. In this work, the lean igni... 展开 The fuel atomization and ignition characteristics of an afterburner under subatmospheric pressure are important foundations for expanding the operating range of the afterburner at high flight altitudes. In this work, the lean ignition limits of the afterburner at subatmospheric pressure were obtained through experiments, and the fuel droplet size distribution and ignition process in the afterburner were acquired using a laser particle sizer and a high-speed camera. The results showed that the ignition equivalence ratio increased as the inlet pressure decreased and was lowest when the flame stabilizer blockage ratio was 0.3. When the inlet pressure of the combustor decreased from high pressure to subatmospheric pressure, the Sauter mean diameter (SMD) range of the fuel droplets increased from 60～110 nm to 100～190 um due to the increase in the ignition equivalence ratio and the deterioration of the fuel atomization characteristics. Under subatmospheric pressure, the flame residence phase time in the ignition process decreases significantly, while the flame intensity fluctuates more dramatically during the flame growth phase due to the decrease in the equivalence ratio of the gaseous phase, the larger fuel droplet size, and the uneven fuel distribution. When the inlet pressure is high pressure, the flame propagates from the ignition position to the trailing edge of the flame stabilizer first and anchors within the shear layer behind the flame stabilizer, whereas under subatmospheric pressure, the flame does not propagate to the anchoring point in the first place, which is one reason for the difficulty of ignition of combustors under high-altitude conditions. 收起