Based on a certain type of direct injection diesel engine

a three-dimensional model of a complete single-cylinder combustion chamber with intake and exhaust ports was established. The three-dimensional computational fluid dynamics (CFD) analysis software CONVERGE was used to simulate the spray

combustion and emissions of the engine. The effect of n-butanol blending ratio on the combustion and emissions of the diesel engines was studied. The results showed that with the increase of the n-butanol blending ratio

the peak cylinder pressure

ignition delay and combustion rate increase

the soot and carbon monoxide emissions gradually reduce

and the nitrogen oxides emissions slightly increase. In order to further improve the combustion and reduce the pollutant emissions of the engine fueled with n-butanol/diesel blended fuel

the combined effects of fuel injection strategy and combustion chamber geometry were studied. The results show that for an engine fueled with the blended fuel

multiple injection and suitable combustion chamber geometry can effectively improve the mixture in the cylinder

increase the turbulent kinetic energy in the cylinder

and further reduce the emissions of soot. Compared with pure diesel fuel

the blended fuel enables multiple injection to further lower soot emissions and simplifies fuel injection strategy

but it weakens the effect of combustion chamber geometry on the soot emissions.