Analysis of Acoustic Excitation Effect on Lean Blowoff in Premixed Bluff Body Flames

예혼합 보염기 화염의 희박 화염 날림에 음향 가진이 미치는 영향에 관한 연구

The blowoff phenomenon was experimentally investigated in a ducted combustor according to the acoustic excitation. The blowoff equivalence ratio rapidly increases at specific acoustic excitation frequencies. A resonance phenomenon occurs when the excitation frequency approaches the harmonic frequency of the combustor. The resonance increases the velocity fluctuation in the combustor and the infiltration velocity of the unburned gas in the shear layer. Consequently, the mixture velocity exceeds the burning velocity and the blowoff occurs at the higher equivalence ratio.