Auto-ignition and deflagration characteristics of ethanol-gasoline/air at high temperature

Abstract

Abstract The ignition delay period and deflagration characteristics of ethanol-gasoline/air mixture under the conditions of high temperature and low pressure were studied by using reflected shock wave in atomizing shock tube. The ignition delay period, combustion pressure and self-illumination intensity of the mixture were measured at a temperature range of 1100–1800\u202fK and a pressure range of 0.1–0.65\u202fMPa with the equivalence ratios of 0.1–2.5. The results show that the ignition delay period of ethanol-gasoline/air mixture is prolonged with the increase of equivalence ratio under high ignition temperature, the correlation between the logarithm of ignition delay period and the reciprocal of ignition temperature is linearly distributed under different pressures, satisfying the Arrhenius relation and having a higher dependence on pressure within the low-pressure range. Severe deflagration happens when the equivalence ratio of the mixture is 1.0 and ignition temperatures are within 1300–1450\u202fK. At this time, the self-luminous intensity of combustion is significantly affected by deflagration, and the light intensity dropped sharply after reaching the peak value. After that, as the ignition temperature increases, the peak value of deflagration pressure gradually decreases, and the self-luminous light maintains a high intensity for a long period of time.