Combustion instabilities in a lean premixed pre-vaporized combustor at high-pressure high-Temperature

Experimental results correlating combustion instability and staging ratio in a RP-3 fueled lean premixed pre-vaporized (LPP) combustor is presented. All the experiments are operated at highpressure and high-Temperature conditions, and processed data has been collected and classified by the staging ratio. A lowfrequency oscillation is found in the conditions that the main stage and pilot stage work together. There are two discrete frequencies laying in 50∼120 Hz and 420∼470 Hz, the former changes with staging ratio (SR) while the latter remains constant. Sensitivity analysis of flame model reveals that the lowfrequency oscillation at 50∼120 Hz is highly suspected to be caused by an intrinsic mode of this combustor. RANS simulation of flame structure finds that delay time could be extended by decreasing SR, which is consistent with the theoretical analysis.