Vibration, noise and exhaust emissions analyses of an unmodified compression ignition engine fuelled with low sulphur diesel and biodiesel blends with hydrogen addition

• Noise and vibration acceleration of engine block decreased with biodiesel usage.
• Hydrogen addition caused to further decrement of noise and vibration acceleration of engine block.
• Biodiesel increased carbon dioxide and nitrogen oxide emissions whereas decreased carbon monoxide emission.
• Carbon monoxide, carbon dioxide, and nitrogen oxide emissions were improved by hydrogen addition.

Depletion thread of fossil fuels and emission regularities of countries enforce researchers to use alternative resources in diesel engines. Hydrogen and biodiesel are one of the most important alternative fuels. Therefore, all effect of them must be investigated on diesel engine. In this study, experimental investigation was conducted on an unmodified four-stroke four-cylinder compression ignition engine, in order to comprehend its noise and vibration characteristics when the engine was fuelled with sunflower, canola, and corn biodiesel blends with %20 and %40 volume ratio while H2 injected through inlet manifold with 3 l/min and 6 l/min flow rates. The results revealed that changes of sound pressure level with H2 addition depended on engine speed whereas vibration acceleration was decreased with addition of gas at all engine speeds. Furthermore, in this paper exhaust emission characteristic of the engine when it was fuelled with sunflower, canola, and corn biodiesel blends and H2 gas addition was presented.