Abstract
High repetition rate simultaneous planar laser induced fluorescence (PLIF) of CH and OH radicals and stereoscopic particle imaging velocimetry (PIV), both at 10 kHz, was developed. The high repetition simultaneous system is applied to methane-air turbulent jet premixed flame to show the performance of developed system. The obtained simultaneous CH and OH PLIF images well represent flame dynamics in turbulent jet premixed flame. Simultaneously obtained three-component velocity vectors also represent relation between fluid velocity and flame dynamics. From temporal analyses, the injection frequency of the large-scale unburnt mixture island is clarified. The creation of small scale unburnt mixture islands from the large scale ones, which may contribute the enhancement of turbulent burning velocity, is also presented. For general understanding of flame structure, Proper Orthogonal Decomposition (POD) analysis has been applied to the OH PLIF images.
