Study on ignition performance of a cavity trapped vortex combustor of the afterburner with an air-blast-swirl atomizer

In order to study the lean ignition characteristics of an air-blast-swirl atomizer in a cavity trapped vortex combustor of the afterburner, an air-blast-swirl atomizer with a flat bell mouth was designed. Through test research and numerical simulation analysis, the characteristics of spray cone angle and lean ignition of the air-blast-swirl atomizer were obtained. The results showed that the spanwise spray cone angle of the air-blast-swirl atomizer was greatly affected by air pressure and oil pressure, while the radial spray cone angle was basically unaffected and kept stable; under the condition of Mach number 0.53, the cavity trapped vortex combustor of the afterburner can successfully ignite with lean ignition at the fuel air ratio of 0.001 79; when the inlet pressure ratio of out and inner bypass was 0.93, the ideal vortex system cannot be formed in the cavity, making it inconducive to the afterburner ignition; and the lean ignition fuel air ratio was 0.00376; if the inlet pressure ratio of out and inner bypass was constant, increasing the inlet pressure could be beneficial to lean ignition of the afterburner; the insertion depth of the igniter had a great influence on the ignition performance of the cavity, and its insertion depth was required to match the radial spray cone angle of the air-blast-swirl atomizer; the wall temperature data of the front wall of the cavity can be used as a criterion for the success of the cavity ignition. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.