Experimental and numerical study on the ignition delay times of dimethyl ether/propane mixtures in O2/CO2 atmospheres

This work measured the ignition delay times (IDTs) of dimethyl ether (DME)/propane mixtures in O2/CO2 atmosphere in a shock tube at an equivalence ratio of 0.5, a temperature range of 1157-1380 K, pressures of 2 and 10 atm, and a DME blending ratio range of 0-100%. A detailed kinetic model referred to as the DME-C3H8 model was constructed based on the OXYMECH 2.0 model and the DME sub-mechanism of Aramco 3.0. The DME-C3H8, Aramco 3.0, NUIG 1.0, and Dames models were evaluated through the IDTs obtained in the present study, and from literature in O2/N2 and O2/Ar atmosphere. The impact of the DME blending ratio was investigated using the DME-C3H8 model, and results show that the IDTs in O2/CO2 atmosphere at pressures of 2 and 10 atm decrease linearly with increased DME blending ratio; there exists a clear synergy effect between DME and propane in the O2/N2 atmosphere at the pressure of 2 atm, which is significantly weakened at the pressure of 10 atm. The impact of CO2 and pressure on the ignition were discussed in detail.

Automated summary

This study measured the ignition delay times of DME/propane mixtures in an O2/CO2 atmosphere and constructed a detailed kinetic model. The results show that the increase in DME blending ratio has a linear effect on the ignition delay times at different pressures. There is a synergy effect between DME and propane in different atmospheres and pressures, and CO2 and pressure have significant impacts on the ignition behavior.