An experimental study of methane–oxygen–carbon dioxide premixed flame dynamics in non-adiabatic cylinderical meso-scale reactors with the backward facing step

Abstract

In the present study, we experimentally evaluated the effects of geometrical parameters, Reynolds number, dilution percent, and equivalence ratio on methane–oxygen–carbon dioxide flame dynamics in non-adiabatic cylindrical meso-scale reactors with the backward facing step. Five flame regimes of blow-out, marginal, stationary (asymmetric and spinning), RERI, and flashback were observed during the tests. The results showed that adding carbon dioxide to methane–oxygen mixture could extend RERI flame regimes in the meso-scale reactors. Moreover, it was shown that the presence of RERI flame regime could lead to more uniform temperature distribution on the outer surface of the lengthy meso-scale reactors as compared to the stationary flame regimes. Also, it was demonstrated that increasing the average flow speed in the meso-scale reactors decreased the average frequency of RERI flame regimes.