Effect of oxygenated fuels on performance, combustion, emission and vibration characteristics of a compression ignition engine

Oxygenated fuels are set to replace fossil fuels, as they are biodegradable, renewable and have less impact on the environmental. Experiments have been carried out to find performance, combustion, emission and vibration characteristics of a single cylinder, four stroke, variable compression ratio, compression ignition engine. In this study, the fuels used are diesel, oxygenated fuels like neem methyl ester (NME), B1 (diesel 50%, neem methyl ester 45%, methanol 5%) and B2 (diesel 50%, neem methyl ester 40%, methanol 10%). Engine tests are conducted at the rated speed of 1500 rpm for different loading conditions at the fixed compression ratio of 17.5. At full load condition, brake thermal efficiency is higher by 24.74% for B2 over diesel. Maximum net heat release rate and maximum rate of pressure rise are higher for NME compared to blends B1 and B2. The smoke density of diesel-biodiesel-methanol blended fuel B1 is low compared to other fuels up to 50% load. At full load condition, vibration is reduced by 36.4, 50.7 and 40.4% for NME compared to diesel at first, second and third highest peak amplitude frequencies. Therefore, NME and diesel-biodiesel-methanol blended fuel B1 are recommended as alternate fuels for a compression ignition engine in view of reduced engine vibration and emissions.