Propagation of Unsteady Tribrachial Flames in Laminar Non-premixed Jets

摘要

The characteristics of propagating tribrachial flames in non-premixed laminar jets have been investigated experimentally. Free jets of methane are ignited downstream with a Nd: YAG laser to eliminate possible flow disturbances during ignition. The flame propagation is visualized an its speed measured by a high-speed shadowgraphy and schlieren technique. Results show that the edge of the propagating flame in a laminar jet regime has a tribrachial flame structure: a lean premixed flame, a rich premixed flame, and a diffusion flame, all extending from a single location.