Study of Transient Effects on the Extinction Limits of an Unsteady Counterflow Diffuison Flame

摘要

Extinction strain rates in unsteady methane- and propane-air counterflow diffusion flames were experimentally measured as a function of initial strain rate, oscillation frequency, and amplitude of the imposed fluctuation. The maximum strain rate was found to occur at a temporal phase corre- sponding to the maximum velocity for the diluted methane flame. However, for the propane flame, the maximums train rate occurred when the imposed velocity fluctuation was zero and decreasing.