An improved H 2/O 2 mechanism based on recent shock tube/laser absorption measurements

Abstract

An updated H 2/O 2 reaction mechanism is presented that incorporates recent reaction rate determinations in shock tubes from our laboratory. These experiments used UV and IR laser absorption to monitor species time-histories and have resulted in improved high-temperature rate constants for the following reactions: H + O 2 = OH + O H 2 O 2 ( + M ) = 2 OH ( + M ) OH + H 2 O 2 = HO 2 + H 2 O O 2 + H 2 O = OH + HO 2 The updated mechanism also takes advantage of the results of other recent rate coefficient studies, and incorporates the most current thermochemical data for OH and HO 2. The mechanism is tested (and its performance compared to that of other H 2/O 2 mechanisms) against recently reported OH and H 2O concentration time-histories in various H 2/O 2 systems, such as H 2 oxidation, H 2O 2 decomposition, and shock-heated H 2O/O 2 mixtures. In addition, the mechanism is validated against a wide range of standard H 2/O 2 kinetic targets, including ignition delay times, flow reactor species time-histories, laminar flame speeds, and burner-stabilized flame structures. This validation indicates that the updated mechanism should perform reliably over a range of reactant concentrations, stoichiometries, pressures, and temperatures from 950 to greater than 3000 K.