Extinguishment of methane diffusion flames by carbon dioxide in coflow air and oxygen-enriched microgravity environments

Microgravity experiments and computations have been conducted to elucidate stabilization and extinguishment mechanisms of methane diffusion flames, in the cup-burner configuration, with CO2 added gradually to a coflowing air or oxygen-enriched stream. The minimum extinguishing concentration of CO2 under low oxidizer velocities (<20 cm/s) was measured in microgravity achieved by parabolic flights of the NASA Reduced Gravity Aircraft. Transient...