UV-visible emission spectroscopy of the combustion process in a common rail CI engine fulled with n-butanol-diesel blends

This paper is focused on the study of the effects of the injection strategy and fuel blends on spray combustion and soot formation in compression ignition engines. UV-visible natural emission spectroscopy was applied in the combustion chamber of a single cylinder high swirl compression ignition engine equipped with a common rail multi-jet injection system. The engine was fuelled with low-sulphur neat diesel and blended with 20 and 40% by volume of n-butanol. For all the fuels, the evolution of radical species, such like OH, and soot was followed during the spray combustion processes examining different pilot-main dwell timings. Optical data were correlated to engine parameters and exhaust emissions.