Structure of diffusion and premixed laminar counterflow flames including molecular radiativa transfer

The interaction between radiation and combustion is studied theoretically in the case of strained counterflow nonluminous laminar flames. Both H$_2$–O$_2$ diffusion and C$_3$H$_8$-air premixed flames are considered. Calculations are based on detailed chemical kinetics and narrow-band statistical modeling of infrared radiative properties. It is shown that radiative transfer decreases the temperature level, which affects particularly the production and consumption of minor species and pollutants. For H$_2$–O$_2$ flames, a low strain rate extinction limit due to radiation is found. It is also shown that the commonly used approximation of optically thin medium is inaccurate, even for the small-scale laboratory flames considered here.