Transition from Branching-Chain Kinetics to Partial Equilibrium in the Combustion of Lean Hydrogen-Oxygen Mixtures in Shock Waves

Abstract
Concentration profiles of the OH radical in the shock‐initiated combustion of lean hydrogen‐oxygen‐argon mixtures at low pressures (∼0.3 atm) and temperatures (∼1400°K) are found to exhibit pronounced spikes prior to attainment of partial equilibrium. It is shown that this effect is not encompassed within the accepted mechanism for the H2–O2 reaction. Possible reconciliations are presented and discussed.