Applicability of Zel’dovich’s theory of chain propagation of flames to combustion of hydrogen-oxygen mixtures

The applicability of Zel’dovich’s theory to the propagation velocity of flames with chain-branching reactions was tested by calculations based on a detailed mechanism and using Zel’dovich’s approximate formulas with a refined mechanism of hydrogen atom recombination for stoichiometric hydrogen-oxygen and hydrogen-air mixtures at pressures of 47.5–760 torr. Good agreement of the results was obtained. Zel’dovich’s approximate theory for a flame with chain-branching reactions dominated by recombination processes gives a reasonable physical picture and provides approximate formulas for flame propagation velocity.