Kaminski, CF; Bai, XS; Hult, J; Dreizler, A; Lindenmaier, S; Fuchs, L, "Flame growth and wrinkling in a turbulent flow", APPLIED PHYSICS B-LASERS AND OPTICS 71:711-716(2000), DOI:10.1007/s003400000425, |
High-speed planar laser-induced fluorescence (PLIF) and 3-D large eddy simulations (LES) are used to study turbulent flame kernel growth, wrinkling and the formation of separated flame pockets in methane/air mixtures. Turbulence was effected by a set of rotary fans situated in a cylindrical enclosure. Flame wrinkling was followed on sequential 2-D OH images captured at kHz repetition rates. Under stoichiometric conditions and low turbulence levels the flame kernel remains singly connected and close to spherical in shape. By increasing turbulence or reducing the stoichiometry of the mixture the formation of separated pockets could be observed and studied. The mechanisms behind these phenomena are investigated qualitatively by LES of a level-set G-equation describing the flame surface propagation in turbulent flows.