SIMULATION OF ELECTRIC-FIELD EFFECTS IN PREMIXED METHANE FLAMES

The objective of this study is to predict the effect of electric fields on the ionic structure of one-dimensional methane flames. The chemical kinetic mechanism devised for this study combines existing methane oxidation mechanisms with a series of chemiionization, ion-molecule, and dissociative-recombination reactions thought to be important to the ionic structure of methane flames. The governing equations include Poisson's equation to describe the electric field intensity in the flames. The model correctly predicted several features in the ionic structure of methane flames. The model was used to predict saturation currents as a function of peak flame temperature from which the apparent activation energy for the saturation process was determined. The predicted apparent activation energy compared well with the experimental range of values. This analysis determined that the rate-limiting reaction in the overall ionic reaction mechanism is: C2H3O+ + H-2 --> H3O+ + C2H2.