Characteristics of opposed flow partially premixed flames in mesoscale channels at low strain rates

摘要: Abstract This study investigates opposed flow partially premixed flames (OFPPFs) in mesoscale horizontal channels. Flame stabilization conditions and behaviors were experimentally investigated for methane propane, based on experimental parameters including velocity, nozzle distance, width, channel gap, the equivalence ratios of mixtures. Various flame structures formulated, as (PPFs) can intrinsically formulate three branches: lean (LPF), non-premixed (NPF), rich (RPF), depending conditions. Three extinction limits obtained: higher strain rate (HSR), lower (LSR), flashback. The HSR extended through premixing increase gap scale. Some distinctive characteristics found LSR conditions, which main focus investigation. More specifically, trends opposite terms sides regarding to ratio, oscillation near was affected by ratio. A simple analysis conducted explain phenomena. It that induced self-propagation a edge faster than velocity. Its periodic motion be explained existence new condition transient variation gas concentrations caused dilution burned along stream. PPFs thermal thickness or effective heat loss from flame. These results not only help us understand combustion spaces, but also provide important clues structure ordinary flames.