A combined computational and experimental study of methane and propane flames burning in air diluted with thermal agents is described. Detailed kinetic modeling of opposed-jet diffusion flames and experimental extinguishing volume fraction measurements for counterflow and coflow diffusion flames are described. It is shown that the hypothesis of a characteristic maximum flame temperature for buoyancy-dominated diffusion flames near extinguishment allows quantitative predictions of agent extinguishing volume fractions for counterflow diffusion flames. The characteristic temperatures differ for methane and propane flames. In general, coflowing diffusion flames require lower volume fractions of a thermal agent for extinction than counterflow flames, but the relative effectiveness of the agents is the same, suggesting that heat loss mechanisms are similar for both types of flame and fuel.
Proceedings Title: Proceedings of the 6th U.S. National Combustion Meeting
Conference Dates: May 17-20, 2009
Conference Location: Ann Arbor, MI
Conference Title: 6th U.S. National Combustion Meeting
Pub Type: Conferences
coflow diffusion flames, counterflow diffusion flames, detailed chemical kinetic modeling, extinguishment, extinguishment temperature, thermal agents