Burning velocities of dimethyl ether (DME)–nitrous oxide (N2O) mixtures

Abstract From a usability and capability perspective, dimethyl ether (DME) fuel with nitrous oxide (N 2 O) as oxidant is a promising combination for next-generation combustion devices or propellants for space vehicles. However, to ensure proper and profitable application of this fuel, we must clarify the combustion characteristics of the DME–N 2 O mixture. To this end, we conducted burning velocity experiments using the closed spherical bomb technique initiated at 0.1 MPa and 295 K and ran numerical models considering the DME oxidation and N 2 O decomposition reaction mechanisms in the DME–N 2 O mixtures. To characterize the N 2 O oxidant, we compared the experimental and theoretical results of DME–N 2 O with those of air and N 2 /0.5O 2 gases as oxidants. Among the three mixtures (containing the same amount of DME 6.54% by volumetric fraction), DME–N 2 O exhibited the lowest burning velocity, although N 2 O has large heat of formation. The experimental burning velocity of DME–N 2 O was slowed by the low thermal diffusivity and the delay caused by the decomposition reactions of N 2 O, N 2 O (+M) ↔ N 2  + O (+M), N 2 O + H ↔ N 2  + OH, and N 2 O + H ↔ NH  +  NO, which are same as those that are considered important in the oxidation of C1–C3 hydrocarbon–N 2 O mixtures.