Inhibition of the reaction between hydrogen and oxygen by multiatomic gas admixtures behind the incident shock wave front

The inhibiting effect of multiatomic gases has been investigated by numerical simulation of hydrogen oxidation with account taken of the nonequilibrium state of the initial components, intermediates, and reaction products behind the shock wave in the framework of a vibrationally nonequilibrated model. The central feature of the model is successively taking into account the vibrational disequilibrium of the HO2 radical as the most important intermediate in the chain branching process. The inhibiting effect can be explained by the influence of the multiatomic gases on the rate of the vibrational relaxation of the vibrationally excited HO2 radical resulting from the reaction. Methane, tetrafluoromethane, fluoromethane, difluoromethane, chlorofluoromethane, formaldehyde, ethane, hexafluoroethane, ethylene, tetrafluoroethylene, and propane have been considered as inhibitory admixtures.