Fluctuation and extinction of laminar diffusion flame induced by external acoustic wave and source.

ABSTRACT: Acoustic wave can destabilize the flame and has a potential in firefighting, but the influences of the sound source and its frequency are still poorly understood. This work applies a loudspeaker to extinguish a laminar diffusion propane flame of 5-25 mm high, where the local sound frequency is 50-70 Hz and sound pressure is 0.8-3.2 Pa (92.0-104.1 dB). Results reveal a constant flame pulsating displacement at the extinction limit, independent of the sound environment used. Such a flame pulsating displacement is found to be caused by the motion of the speaker membrane (or diaphragm) and its induced wind, which could be two orders of magnitude larger than the displacement of the air that transmits acoustic wave. Thus, under the influence of sound source, a critical flame strain rate, stretche

SUBMITTER: Xiong C 

PROVIDER: S-EPMC8277839 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature