Dynamic flashback induced by sound wave in a premixed bluff-body stabilized flame

Flashback is a critical issue for premixed flame, because it can result in increased pollutant emissions and serious mechanical damage. In this study, the sound wave is used to induce velocity fluctuation which further induces the flashback. The structure of the dynamic flashback induced by sound wave in a premixed bluff-body flame is studied using a high-speed camera. The sound pressure level is fixed at 94 dB and the sound frequency is set at 10 Hz, 30 Hz and 60 Hz, respectively. The flame images show that the transient structure of flashback can be obtained clearly by the high speed camera and the structure of flashback at different sound frequency is different. This indicates that the oscillation frequency of the instable flame affects the structure of flashback seriously.