An improved H_2/O_2 mechanism based on recent shock tube/laser absorption measurements

摘要

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_2O_2(+M) = 2OH(+M) OH + H_2O_2=HO_2+H_2O O_2 + H_2O = 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_2/O_2 decomposition, and shock-heated H_2/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.