Study of Combustion Characteristics of an SI Engine Fuelled with Ethanol and Oxygenated Fuel Additives

Abstract

This study investigates the effects of ethanol-blended gasoline with oxygenated additives on a multi – cylinder Spark Ignition (SI) Engine. The experiments were conducted in two stages. In stage I, the test fuels were prepared using 99.9% pure ethanol and gasoline with a cycloheptanol blend, in the ratio of E69.5 + 0.5 cycloheptanol, E64.6 + 0.4 cycloheptanol, E59.7 + 0.3 cycloheptanol, E49.8 + 0.2 cycloheptanol. The remainder was gasoline. In stage II, the test fuels were prepared using 99.9% pure ethanol and gasoline with cyclooctanol blend, in the ratio of E69.5 + 0.5 cyclooctanol, E64.6 + 0.4 cyclooctanol l, E59.7 + 0.3 cyclooctanol, E49.8 + 0.2 cyclooctanol. The remainder was gasoline. Performance and emission tests were conducted on a multi – cylinder SI Engine coupled with an eddy current dynamometer. The emission tests were measured using an exhaust gas analyzer. The experimental results proved that the blend increased brake thermal efficiency more than a sole fuel, such as gasoline. The emission tests found that the CO slightly decreased, while HC and O₂ increased moderately and CO₂ and NO_x appreciably decreased. In addition, combustion analyses were made with the help of combustion analyzer, in which cylinder pressure and heat release rate were analysed.