CONTROLLED TRANSITION TO CELLULAR FLAME FRONTS.

A nonlinear control mechanism is proposed to reduce flame instabilities. An instability associated with the formation of cellular flames is known to occur when the mass diffusivity of the deficient reactant in a combustible mixture is sufficiently larger than the diffusivity of the mixture. The transition from the smooth front to the cellular structure can be analyzed by deriving an evolution equation for flame front disturbances. This nonlinear equation depends on the position of the flame, which is a function of time controlled by the underlying prescribed flow. Both linear and time-periodic functions are considered and the transition to cellular structures is shown to be either considerably delayed or eliminated.