The Extinction of Slowly-Varying Nonadiabatic Flames

Using the techniques of large activation energy asymptotics, we observe that a slowly-varying planar nonadiabatic flame will extinguish (1) as the burning rate approaches zero, rather than at finite burning rate as predicted by the steady theory, and (2) at a finite position, when subjected to a wide class of external stimuli. An example is given in which the external stimuli arises from either fuel or concentration variations ahead of the flame.