Structure and stabilization mechanism of a stratified premixed low swirl flame

Paper in proceeding, 2010

Simultaneous OH-, fuel- planar laser induced fluorescence (PLIF) and particle image velocimetry (PIV) measurements were performed in turbulent low-swirl stratified premixed flames. Acetone was used as a fuel tracer and seeded in to the lean premixed methane/air flow. A laser at 283 nm was used for both the fuel-, and OH-PLIF measurements. For PIV two Nd:YAG lasers operating at 532 nm were used. The combined PIV/PLIF images revealed e.g. the fuel distribution, entrainment of ambient air, mixing with the air/fuel stream and the resulting stratification in the trailing edge of the flame. Furthermore, the combined PLIF images visualized the preheat layer (> 1000K) and flame front location. Pockets of unburnt reactants were occasionally detected above the local flame front as a result from the flame wrinkling and following flame pinching. From the simultaneous PIV data flame-flow interaction was investigated including the large-scale vortex structures continuously created in the outer shear layer and its influence on the flame stabilization.