Chain-thermal flame propagation

Abstract

1. Relations were obtained for determining the rate of flame propagation taking into account the following effects: linear chain branching and termination rates, second order chain termination rates, chain initiation rates, thermal conductivity and the diffusion coefficient of the active center. 2. From these relations it follows that second order chain termination has a greater effect on the flame propagation rate, the lower the combustion temperature and the smaller the ratio of the product of the heat capacity and density and the diffusion coefficient to the thermal conductivity. With a decrease in this ratio or with a fall in the active center concentration at the combustion temperature, the effect of linear chain branching and termination on the flame propagation rate increases as in these cases there is a relative fall in the number of active centers transferred by diffusion. 3. The relations obtained were applied to two cases of hydrazine decomposition flames and the calculations illustrate the effect of second order chain termination and linear chain branching on the flame propagation rate.