Experimental and numerical study on the ignition delay times of dimethyl ether/ethane/oxygen/carbon dioxide mixtures.

• Ignition delay times of dimethyl ether/ethane/O 2 /CO 2 mixtures were first provided. • OXYMECH predicts well on the IDTs of the mixtures in O 2 /CO 2 and O 2 /N 2 atmosphere. • IDTs of the mixtures first decrease and then increase as adding DME at 10 atm. • The effect of DME addition and CO 2 on the IDTs of the mixtures were analyzed. The ignition delay times (IDTs) of dimethyl ether (DME)/ethane/O 2 /CO 2 mixtures were measured in a shock tube at pressures of 0.8, 2, and 10 atm; temperatures within the range of 1126–1449 K; equivalence ratio of 0.5; and DME proportions within the range of 0–100%. Four chemical kinetic models named OXYMECH, AramcoMech 3.0, San-Diego 2016 and Wang-DME were validated using the IDTs measured in this work. The results indicate that the OXYMECH predicts well the experimental data under O 2 /CO 2 and O 2 /N 2 atmospheres. At P = 0.8 and 2 atm, T = 1300 K, the increase of the DME proportion inhibits the ignition of the mixtures under O 2 /N 2 and O 2 /CO 2 atmospheres. At P = 10 atm, T = 1300 K, the IDTs of the mixtures firstly decrease when DME proportion increases from 0 to 20%, and then increase when DME proportion increases from 20 to 100% under O 2 /CO 2 atmosphere, while the IDTs of the mixtures increase as the DME proportion increases under O 2 /N 2 atmosphere. The valley-values of the IDTs of the mixtures appear at the certain DME proportion at P = 10 atm, T = 1100 K and 1200 K under O 2 /N 2 and O 2 /CO 2 atmospheres. The analyses of sensitivity and the rate of production were conducted to interpret the effect of DME addition and the properties of CO 2 on the ignition of the DME/C 2 H 6 /O 2 /CO 2 mixtures. [ABSTRACT FROM AUTHOR]