Sakane, R., Fujimura, T., Seo, T., and Mikami, M., "Combustion and Noise Characteristics in a Diesel Engine with Hydrogen Addition and Pilot Injection," SAE Technical Paper 2015-01-1922, 2015, doi:10.4271/2015-01-1922.
We experimentally investigated effects of pilot diesel-fuel injection on ignition timing variation and noise reduction in a diesel engine with hydrogen addition to the intake pipe. The pilot diesel-fuel injection suppressed ignition timing variation which was significant under hydrogen addition conditions. The heat release by the pilot diesel-fuel injection stably acted as an ignition source of the hydrogen-air mixture. The maximum in-cylinder pressure rise rate increased with the hydrogen fraction. However, the sound pressure level attained minimum around a specific hydrogen fraction.