Evaluation of Performance Parameters of Direct Injection Spark Ignition Engines Fuelled with Alcohol-Gasoline Blends

This study investigates the performance parameters of Direct Injection Spark Ignition (DISI) engines fuelled with alcohol-gasoline blends under varying engine loads and speeds, focusing on methanol, ethanol, butanol and gasoline blends. Alcohols have been recognized for their potential to improve engine performance and reduce harmful emissions due to their higher oxygen content and favourable combustion characteristics. The experimental tests were conducted using a single-cylinder DISI engine under controlled laboratory conditions. Pure gasoline and two alcohol-gasoline blends were tested at different engine loads (0%, 50%, and 100%) and speeds (2500, 3000 and 3500 RPM). D-optimal Response Surface Methodology (RSM) design of Design-Expert version 13.0.1with eleven experimental runs, two factors and seven responses were used for the experimental design and to construct mathematical models for the performance parameters. The adequacy of the models was determined by statistical methods and the best fit model for each response was selected and analysis of variance was applied for a better understanding of model attributes. The results show that alcohol-gasoline blends significantly improve the combustion efficiency of DISI engines. The thermal efficiency of the alcohol-gasoline blend increased slightly by 0.9% compared with that of pure gasoline The addition of alcohols led to an increase in Brake Specific Fuel Consumption (BSFC) by up to 1.89% and engine torque exhibited a marginal improvement. The study concludes that alcohol-gasoline blends can serve as viable solutions to meet future energy efficiency goals in the automotive industry, while also contributing to the reduction of fossil fuel consumption.