Suppressing oscillation method of supersonic combustion and flow in transitional cavity

Targeting the phenomenon of non-reacting flow self-excited oscillation in a traditional cavity with a length-to-depth of 10.0 under the isolator entrance condition of Mach number 3.0, a scheme to suppress the oscillation by adding a rib in the cavity was proposed. Through experiments and numerical calculations, the effect of this scheme on suppressing oscillation was verified, and the differences in the flow field structure and combustion performance of the combustor with/without the rib were analyzed. It was found that adding a rib in the cavity can effectively eliminate the self-excited oscillation of 175.8 Hz under the non-reacting flow condition, and the reacting flow field was more stable. The flame stabilization ability of the cavity was reduced after the rib was added, and some kerosene not completely burned in the cavity continued to react after entering the divergent section, so as to extend and enlarge the combustion zone downstream. The combustion efficiency and net thrust of the engine were reduced by 5.4% and 8.9%, respectively, but the thrust was more stable. The peak value of one-dimensional averaged heat flux was also reduced from 2.9 MW/m2 to 1.8 MW/m2, which optimized the thermal environment of the combustor. © 2023 BUAA Press. All rights reserved.