Remaining uncertainties in the kinetic mechanism of hydrogen combustion

An analysis of the performance of an updated hydrogen combustion mechanism is presented. Particular attention was paid to different channels of reaction between H atoms and HO2 radicals, to pressure dependence of the recombination of HO2 radicals, and to the anomalous rate constant of reaction between OH and HO2 radicals. The contemporary choice of the reaction rate constants is presented with the emphasis on their uncertainties. Then the predictions of ignition, oxidation, flame burning velocities, and flame structure of hydrogen–oxygen–inert mixtures are shown. The modeling range covers ignition experiments from 950 to 2700 K and from subatmospheric pressures up to 87 atm; hydrogen oxidation in a flow reactor at temperatures around 900 K from 0.3 up to 15.7 atm; flame burning velocities in hydrogen–oxygen–inert mixtures from 0.35 up to 4 atm; and hydrogen flame structure at 1 and 10 atm. Comparison of the modeling and experiments is discussed in terms of the range of applicability of the present detailed mechanism. The necessity for analysis of the mechanism to have an exhaustive list of reactions is emphasized