LEAN AND RICH PREMIXED DIMETHOXYMETHANE/OXYGEN/ARGON FLAMES: EXPERIMENTAL AND MODELING

Experimental structures of two dimethoxymethane/oxygen/argon flames at equivalence ratios of phi = 0.24 and 1.72 have been studied by mass spectrometry. The detected species throughout the flame thickness were H-2, CH3, CH4, H2O, C2H2, CO, CH2O, CH3O, O-2, Ar, CO2, C2H4O2, and C3H8O2. The aim of this work was to extend an original model for ethylene combustion by building a sub-mechanism taking into account the formation and the consumption of oxygenated species involved in dimethoxymethane oxidation. By using kinetic data from the literature, the authors elaborated a new mechanism containing 480 reactions involving 90 chemical species in order to simulate these dimethoxymethane flames. The mechanism provides numerical results, which are in good agreement with experimental data for all species detected in both flames. Whatever the equivalence ratio of the flame, the two main degradation pathways of dimethoxymethane are the same: CH3OCH2OCH3 -> CH3OCH2OCH2 -> CH3OCH2 -> CH2O and CH3OCH2OCH3 -> CH3OCHOCH3 -> CH3OCHO -> CH3OCO -> CH3O -> CH2O, with the first being the fastest.