Measurement of propagation speeds in adiabatic flat and cellular premixed flames of C2H6+O2+CO2

Abstract

Adiabatic burning velocities of premixed flat flames and propagation speeds of adiabatic cellular flames of mixtures of ethane+oxygen+carbon dioxide are reported. The oxygen content O2/(O2+CO2) in the artificial air was varied from 26 to 35%. Nonstretched flames were stabilized on a perforated plate burner at 1 atm. A heat flux method was used to determine burning velocities under conditions when the net heat loss of the flame is zero. Under specific experimental conditions the flames become cellular; this leads to significant modification of the flame propagation speed. Measurements in cellular flames are presented and compared with those for laminar flat flames and also with qualitative predictions of a theoretical model. The onset of cellularity was observed throughout the stoichiometric range of the mixtures studied. Cellularity disappears when the flames become only slightly subadiabatic.