Investigating Knocking Potential, Cycle Stability, and Emission Characteristics in Lean Spark Ignition Engine with Gasoline, Ethanol, and Methanol

This research examined the use of gasoline-ethanol-methanol on the performance of Spark ignition engine with a focus on a ternary fuel mix (gasoline, ethanol and methanol). It also investigated the various combustion characteristics in lean conditions, such as the potential for knocking, ignition delay, and engine performance. Methanol was added to mitigate knocking potential when used in small quantities and reduce ignition delay times during combustion, specifically at leaner air-fuel mixtures. The best decrease in ignition delay was observed with the E5M15 blend, where λ at values of 1.3 and 1.0 had E5M15 SoC of 325 CA° and 3215 CA°, respectively. The CCV results showed a more sloping increase in COV (coefficient of variation) value when using GEM fuel, particularly with the addition of more methanol. Furthermore, methanol was used to increase combustion progression and the ability of the fuel blend to sustain combustion under lean conditions. The torque and power units are not significantly different at values of 1.0, 1.1, and 1.2, but different below 1.3.