On the Structure and Extinction Dynamics of Partially-Premixed Flames: Theory and Experiment

Publisher Website
Google Scholar
Abstract
The interaction and extinction dynamics of a partially-premixed flame ensemble, consisting of a premixed flame and a nonpremixed flame, are theoretically and experimentally studied for the counter-flow configuration generated by a premixed fuel/oxidizer/inert stream and a fuel/inert stream. Separate asymptotic analyses are performed for the structure and extinction of a single merged flame, a binary premixed-nonpremixed flame and a binary premixed-premixed flame; in the last case it is recognized that under certain situations a nonpremixed flame can exhibit the characteristics of a premixed flame. Theoretical results show that the extinction of a binary flame always occurs in a single stage, with the individual flames separated. The extent of separateness can be further modified by the preferential diffusion nature of the mixture. These predictions are completely substantiated by experimental results obtained by using mixtures consisting of methane, ethane or propane as the fuel and O2/N2 as the oxidizer.