Hydrogen–oxygen reactions behind shock waves assisted by OH(2Σ+) formation

The results of the OH(2Σ+) → OH(2Π) luminescence registration at 1000⩽T⩽2500 K and 2.0⩾p⩾0.3 atm during the ignition–combustion process behind incident shock waves in (2H2 + O2) + Ar mixtures were subjected to theoretical analysis. Experiments are interpreted in terms of kinetic problem with account of the electronically excited particles OH(2Σ+), O(1D), and O2(1Δ), and the vibrational nonequilibrium of initial H2 and O2 molecules. Slow vibrational relaxation of O2 molecules exerts essential influence on the chemical transformation process through the chain branching reaction H + O2→HO + O. The maximum luminescence moments calculated are in good agreement with observed ones.