Experimental investigation of performance improving and emissions reducing in a two stroke SI engine by using ethanol additives

In present study, the operational parameters for a two stroke gasoline engine such as delivery ratio, scavenging efficiency, trapping efficiency, etc. have been investigated experimentally when its fuel is blended with ethanol additives. Also the amounts of emitted pollutants (HC, CO, CO2 and NOX) from this engine are measured in various engine velocity and loads. In experiments, ethanol is combined with gasoline in different percentages of 5%, 10% and 15%. The experiments have been done for 2500, 3000, 3500 and 4500 rpm. The results show that in most test cases, when alcoholic fuel is used, scavenging efficiency and delivery ratio increased due to rapid evaporation of ethanol, but fuel converging efficiency and brake specific fuel consumption (BSFC) decreased. The most outstanding result of using ethanol additive is significant reduction in pollutions emitted from engine and CO with 35% reduction has the most reduction percentage among other pollutants.