Effect of alcohol addition to diesel on engine performance, combustion and emission characteristics of a CI engine

A mathematical simulation has been performed to investigate the energetic, combustion and environmental behavior of a mono cylinder, water cooled, four stroke DI diesel engine fuelled with diesel, diesel-ethanol (15% by volume) and diesel-methanol (15% by volume) blends. The results show that alcohol blending to diesel reduces the emissions of NO_x, smoke opacity, specific PM and specific CO₂. From the performance aspect, brake thermal efficiency is found to be higher with both the alcohol-diesel blends compared to neat diesel. However, brake specific fuel consumption is also slightly higher than conventional diesel. The maximum pressure and temperature rise during combustion are less than diesel which is reflected in the results of emissions also. The higher ignition delay of alcohol-diesel blends results a higher heat release rate compared to neat diesel as the premixed phase of combustion is more predominant with alcohol-diesel blends.