Structure of detonation propagating in lean and rich dimethyl ether-oxygen mixtures - Chemical Kinetics in Shock and Detonation Wave

In the present study, the structure of detonations propagating in lean and rich dimethyl ether-oxygen, DME-O2, mixtures has been investigated using steady one-dimensional and unsteady two-dimensional numerical simulations. The origin of the non-monotonous energy release profile in rich DME-O2 mixtures has been explained based on the analyses of the energy release rate per reaction and of the rate of production of the major species. The numerical soot foils and schlieren fields obtained for DME- O2 mixtures demonstrated significant differences as compared to those obtained for H2-NO2/N2O4 mixtures which exhibit non-monotonous energy release profile and a clear double cellular structure. Chemical kinetics considerations tend to indicate that the structure of the energy release profile of detonation in rich DME-O2 mixtures do not fulfill the critical conditions for the existence of a double cellular structure.