Autoignition characteristics and kinetic modeling of an oxygenated gasoline

Ethanol-containing gasoline offers a renewable and cleaner-burning alternative to traditional gasoline, thereby promoting a more sustainable and environmentally friendly transportation system. The shift towards ethanol-enhanced fuels aligns with global efforts to transition towards a low-carbon future in the transportation industry. This work explores ignition delay times of a certification oxygenated gasoline (Euro 6 E10) using a high-pressure shock tube (HPST) and a rapid compression machine (RCM) across a wide range of temperatures (658–1445 K), equivalence ratios (φ = 0.45, 1, 1.5), and pressures (20, 30, and 40 bar). The experimental results demonstrate that ethanol-containing gasolines exhibits similar reactivity as non-oxygenated gasolines at the high-temperature regime. However, at intermediate temperatures and up to the onset of NTC, gasolines with higher ethanol content display longer ignition delays compared to those with lower ethanol content and non-oxygenated gasolines, regardless of the octane characteristics of the fuel. At lower temperatures, Euro 6 E10 reactivity is influenced by the octane characteristics of the fuel. The measured data are compared to simulations using various surrogates, containing three to nine components, developed in the current work. A compact gasoline surrogate model is assembled, comprising of a comprehensive kinetic model (NUIGMech1.2) augmented with recent updates and appropriate sub-mechanisms from the literature. The proposed model is capable of reproducing the autoignition behavior of various oxygenated gasolines across a range of conditions. Sensitivity analyses were performed to elaborate the differences of various surrogates and to highlight the effect of fuel composition on oxygenated gasoline reactivity characteristics.