Structure of opposed jet turbulent premixed flames

In this study, a new ceramic-opposed jet burner was designed to ensure the adiabaticity of the flame. In the opposed-jet-turbulent premixed flame, the concentrations of various stable species as well as the mean flame tempera ture distributions and structures have been investigated. In the present bu rner, turbulent premixed flame can persist far beyond the stretch rate at w hich the wrinkled laminar flame is usually extinguished. The results show t hat the flame structure consists of the stretched stringy vortices involvin g various reacting species (e. g., C3H3, hydrocarbons, O-2) which are refer red to as the distributed reaction zones, and that the flames are divided i nto two categories: (1) transition flame from a wrinkled laminar flame to a distributed reaction zone, and (2) a fully developed distributed reaction zone. The structure of the distributed reaction zone depends mainly on the mixture jet velocity and is independent of the equivalence ratios. The stre tched stringy vortice of the distributed reaction zone eradicates the nonun iformity of temperature and concentration fields. The hydrocarbon species a s well as fuel are completely consumed in the distributed reaction zone, an d almost complete combustion is achieved.