文摘
Autoignition of dimethyl ether in air was studied in a turbulent flow-reactor with optical access, at conditions relevant to micro gas turbine combustors. The ignition process was visualized using OH*-chemiluminescence imaging, showing the formation of multiple autoignition kernels along the central axis of the reactor. Ignition delays in the range of 蟿 = 112鈥?10 ms were measured at temperatures of T = 739鈥?02 K, pressures of P = 0.2鈥?.4 MPa, equivalence ratios of = 0.225鈥?.675, and initial flow velocities of Ui = 8鈥?6 m/s. The effect of adding nitrogen to the reactants as a diluent was investigated for mole fractions of additional nitrogen ranging from 0 < XN2 < 0.1. The experimental ignition delays were compared with homogeneous gas-phase chemical kinetic modeling. Comparison between the modeling and experiments showed significant discrepancies, but agreement was improved when heat transfer in the reactor was taken into account in the modeling.