Vibration and noise characteristics of CI engine fueled with Niger seed oil methyl ester blends and hydrogen

The present study dwells the assessment of vibration and noise levels with the use of biodiesel and hydrogen in dual fuel mode in a single-cylinder, 4-stroke CI engine at different compression ratios (16, 17.5, and 18.5). Niger seed oil methyl ester (NSOME) blends B10, B20, and B40 were used as test fuels and conducted the experimental test at full load (12 kgf) by maintaining the constant engine speed of 1500 rpm. Further, the blend B20 was enriched with different hydrogen flow rates of 5 lpm, 10 lpm, and 15 lpm. The vibration (velocity) and noise levels were measured at the engine body and estimated in terms of RMS values for different test fuels. The vibration levels were decreased when operated with NSOME blends, and B20 has shown fewer vibrations at all the compression ratios compared to other test fuels used. Similarly, the noise levels of NSOME blends were observed to be lower than diesel fuel. Further, the vibration and noise levels of B20 were decreased at higher flow rates of hydrogen. For all the test fuels used, the increasing trend of vibrations was observed at higher compression ratios.