10 kHz SPIV/OH-PLIF simultaneous measurements in premixed turbulent Bunsen flames

Abstract

The dynamics and properties of a premixed turbulent flame, formed in the presence of subsonic, high speed, homogenous, nearly isotropic turbulence in an unconfined system are experimentally investigated. The experiments are performed using simultaneous time-resolved measurements of particle image velocimetry and planar laser-induced fluorescence of OH radicals. Five mean stream wise bulk exit velocities of: 3.35, 6.97, 11.34, 16.84, and 24.79 m/s for lean (φ = 0.8) methane/air mixture with different percentages of H2 addition. The flame front topology has shown a strong dependence on the turbulence intensity in terms of exhibiting folded and convoluted flame sheet structure. Moreover, the addition of H2 changes significantly the flame structure, in terms of flame length and wrinkling due to the high reactivity of methane/H2/air mixture. For flames with high bulk exit velocity, local quenching and healing processes are likely; its probability is reduced with H2 addition.