Flame structure and kinetic studies of carbon dioxide-diluted dimethyl ether flames at reduced and elevated pressures

摘要: Abstract The flame structure and kinetics of dimethyl ether (DME) flames with without CO2 dilution at reduced elevated pressures were studied experimentally computationally. species distributions DME oxidation in low-pressure premixed flat measured by using electron-ionization molecular-beam mass spectrometry (EI-MBMS) an equivalence ratio 1.63 50 mbar. High-pressure speeds lean rich a nearly-constant-pressure vessel between about 1 20 bar. experimental results compared predictions from four kinetic models: the first was published Zhao et al. (2008) [9] , second developed Lawrence Livermore National Laboratory (LLNL) (Kaiser al., 2000) [13] third has been made available to us as Aramco mechanism (Metcalfe 2013) [14] ; fourth, we have used updated model this study. Good agreement found measurements all models for major most typical intermediate addition experiments. However, none able reliably predict high-pressure speeds. Although improved prediction mixtures, errors remained conditions pressure, likely due uncertainty rates CH3 + H(+M) = CH4(+M) branching termination reaction pair CH3 + HO2 = CH3O + OH CH3 + HO2 = CH4 + O2. considerably decreased speed. Kinetic comparisons inert chemically active showed that affects differently. For flames, both third-body effect reduce H-atom production. increases production via HCO(+M) = H + CO(+M) suppression shifting equilibrium CO + OH = CO2 + H.