Experimental investigation of exhaust temperature and delivery ratio effect on emissions and performance of a gasoline–ethanol two-stroke engine

In this study, the effects of ethanol additives (5%, 10% and 15% in volume) on the performance and emissions (HCs, CO, CO2 and NOx) of a SI two stroke engine is investigated in different loads and speeds. Also, the effect of exhaust temperature and delivery ratio on emissions and engine performance is discussed. Results show that in most test cases, when alcoholic fuel is used, scavenging efficiency and delivery ratio increased due to rapid evaporation of ethanol and outcomes of scavenging and trapping efficiencies are in more accordance with the perfect mixing model. The most outstanding result of using ethanol additives is significant reduction in pollutions emitted from engine of which CO with 35% reduction has the most reduction percentage among other pollutants. Although most emissions are increased by increasing the exhaust temperature, but hydrocarbons (HCs) on an average decreased by 30% on increasing the exhaust temperature.