HEAD-ON QUENCHING OF A PREMIXED FLAME BY A COLD-WALL

We examine the premixed flame (PF) quenching problem, where an initial ly steadily propagating flame front impinges on a cold isothermal wall . We employ the simplest possible kinetics, R --> P with a reaction or der of unity, and we restrict ourselves to unit Lewis number. We formu late the problem in terms of the excess enthalpy function, H = tau + Y - 1. Interpretations are provided for the inflection points and maxim s of various functional behaviors; for instance, flame arrest occurs a t the inflection point of Y(0, t) whereas extinction occurs at the max imum of the cold wall H-gradient. The numerical solution code FRAPPE i ntegrates formulae obtained from a simplified set of the conservation equations. Our results compare well qualitatively and quantitatively w ith the full numerical solutions of the original equations.