Edge-flames and cellular structures in oscillatory premixed counterflows

We examine edge-flames in the context of symmetric counterflows of fresh mixture, and examine their dynamics when the rate of strain is varied periodically in time. For a Lewis number of 1, extinction boundaries and zero (in the mean) edge propagation speed boundaries are constructed in the forcing amplitude-Damköhler number plane. Forcing can turn advancing edges into retreating edges. For a Lewis number of 0.3, the fundamental distinction is between flames that display cellular structures and flames that do not. Forcing can convert a non-cellular flame into one with cells; and it can strongly affect the dynamics of cellular structures that exist in the absence of forcing.