An experimental study was performed to investigate the roles of triple flames and flame front instabilities in the blowout transient process. Two-dimensional laser-induced predissociative fluorescence (LIPF) OH and particle image velocimetry (PIV) diagnostic techniques were used for measurements of instantaneous flame structure and velocity data. Initial conditions were aligned by external acoustic excitation and triggering. The blowout transient process can be divided into four regions: the pulsating, onset of receding, receding, and extinction regions, according to the dynamic characteristics of the flame. In the pulsating region, the flame base is basically pulsating at two specific heights with jittering. Flame from instability may play a role in leading to the onset of blowout process. Both LIPF OH image and PIV results show the possible existence of the triple-(or edge-) flame structures in the flame base in the pulsating and onset regions. High strain rate, higher than the extinction strain rate, encountered by the flame base in the onset region should be considered as a prominent factor for the blowout process.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Mechanical Engineering
- Physical and Theoretical Chemistry