NUMERICALLY PREDICTED STRUCTURE AND BURNING VELOCITY OF PREMIXED CO-AR-O-2-H-2 FLAMES INHIBITED BY CF3H

This paper presents the first detailed numerical calculations of the s tructure of carbon monoxide-hydrogen-oxygen-argon flames inhibited by CF3H. Numerical solution of the equations of mass, species, and energy conservation are performed using a chemical kinetic mechanism recentl y developed at the National Institute of Standards and Technology. The calculated burning velocities are compared with a set of previously p ublished experimental measurements performed by another laboratory whi ch encompass a range of equivalence ratios and argon, hydrogen, and in hibitor mole fractions with corresponding burning velocities of 21 to 199 cm/s. The effects of the inhibitor on the species profiles for the major products, radicals, and fluorinated compounds are determined, a nd the major reaction pathways for consumption of the inhibitor are di scussed. The previously published experimental burning velocities are in good agreement with the results of the present calculations for mos t of the conditions tested. For those conditions (high fluorine-to-hyd rogen ratio in the reactants) where the disagreement is largest, the r ate expressions which most influence the burning velocity have been id entified. The modeling results indicate that in CO flames (in contrast to hydrocarbon flames) oxygen atom reaction with the inhibitor and in hibitor fragments is a major decomposition pathway, especially when th ere is a high fluorine-to-hydrogen ratio in the reactants.