A CFD Study on the Effects of Injection Timing and Spray Inclusion Angle on Performance and Emission Characteristics of a DI Diesel Engine Operating in Diffusion-Controlled and PCCI Modes of Combustion

In three-dimensional (3D) computational fluid dynamics (CFD) simulations, the effects of injection timing and spray inclusion angle (SIA) on performance emissions diffusion-controlled Premixed Charge Compression Ignition (PCCI) combustion in part load for a heavy-duty direct (HDDI) diesel engine are studied. The start (SOI) 146° SIA injector is varied between ?70 ?10 °crank (°CA) after top dead center (ATDC). For ?50 °CA ATDC SOI with various SIAs 80° 146°, PCCI reduces mono-nitrogen oxide (NOx) significantly compared to conventional (CDC). Due incomplete rich zones formed by droplet–cylinder wall interaction, early wide deteriorates efficiency (CE) Indicated Mean Effective Pressure (IMEP) increases soot carbon monoxide (CO) emissions. Narrow-angle sprays interacting piston bowl elevate CE IMEP decrease CO but NOx Optimal achieved avoiding fuel interaction. By spray-targeting at stepped lip bowl, 100° yield, respectively, highest IMEP: 97.8% 3.37 bar lowest emissions: 33.5 2.2 ppm, acceptable