The main purpose of this study was to investigate how a narrow angle injector affects the combustion
and exhaust emissions characteristics in a single-cylinder diesel engine fueled by diesel–bioethanol
blends. This study focused on reducing HC and CO emissions in the exhaust emissions by the bioethanol
blending of diesel. A narrow angle injector with an injection angle of 70 was used and compared with a
conventional angle injector having a 156 injection angle. The bioethanol was blended with the conventional
diesel up to 30% with 5% biodiesel. Experiments revealed that, in a narrow angle injector, the premixed
combustion duration increased with bioethanol contents unlike the similar value of conventional
injector. The premixed combustion phasing decreased with the increase of bioethanol in both injectors.
The variation in the peak combustion pressure of the narrow angle injector was smaller than that of a
conventional injector. In addition, the narrow angle injector induced a higher indicated mean effective
pressure (IMEP) and a shorter ignition delay compared to the conventional injector. In terms of exhaust
emissions characteristics, the low and stable ISHC and ISCO emissions can be achieved through the application
of narrow angle injector to the diesel–bioethanol blends combustion. By the early injection combustion
strategy, ISHC and ISCO emissions are significantly reduced.