Experimental Investigations of Noise, Vibration and Combustion Characteristics of Diesel and Pongamia Biodiesel Blends on a CI Genset Engine

Compression Ignition engines are widely used for irrigation purpose in rural areas, which generate more noise and vibrations. In this research, neat diesel and Pongamia biodiesel blend (B20) were fuelled in a compression ignition engine to study its noise, vibration and combustion characteristics at the fuel injection pressure of 200 and 250 bar and the fuel injection timings of 21, 23 and 25 degree bTDC at a constant engine speed of 1500 rpm under various loading conditions from no load to full load. From the experimental results, a strong correlation was observed between the heat release rate and the engine noise as the heat release rate was directly proportional to the magnitude of the engine noise. The noise level found increased with increasing load while running on diesel and decreased while running on biodiesel. The maximum noise level of 80.3dB and 78.3dB was observed at 60% load condition for the diesel and biodiesel blend respectively. Since biodiesel has a higher Cetane number, the ignition delay was found reduced and cause for premixed combustion, which is directly related to the reduction of the rate of pressure rise that reflected in reduced noise level. The vibration in Y-axis found decreased for the B20 fuel blend when compared to the neat diesel. A significant reduction in noise and vibrations are observed at the fuel injection timing of 23 & 21degree bTDC respectively at the fuel injection pressure of 200 bar.