Experimental and simulated study on the ignition delay time of dimethyl ether/n-heptane/oxygen/argon mixtures

•Ignition delay times of n-heptane/DME were measured in the various blending ratio.•A blended model shows favorable performance on the prediction of the ignition delay times.•The effect of DME addition on the IDTs of fuel mixtures were analyzed in detail. The addition of oxygenated fuels to fossil fuels has been considered as a promising approach for reducing the issues associated with hazardous substances. The ignition delay time data of dimethyl ether/n-heptane mixtures were obtained using a shock tube under the following conditions: pressures of 0.8, 4.5, and 10 atm; equivalence ratio of 1; temperature within the range of 1171–1571 K; and dimethyl ether proportion within the range of 0–100%. The Arrhenius dependence of the ignition delay times on temperature and pressure was fitted. The experimental results show that the ignition delay times of dimethyl ether/n-heptane mixtures are less than those of pure dimethyl ether and pure n-heptane within a certain blending ratio range. A combined model named “blended model” was proposed based on the LLNL n-heptane version 3.1 and Zhao dimethyl ether models. The effect of DME addition on the IDT of the fuel mixtures was investigated using the blended model in detail.