A Ford 1.8 l high-speed diesel engine (HSDI) is utilized for a thorough investigation of split dual injection with two included-angle nozzles. The system is equipped with variable-geometry turbocharging (VGT) and high-pressure common-rail (HPCR) technologies which lets multi-injections per cycle. The share of fuel between pulses is divided into three portions of 70-30, 80-20, and 90-10 with included angles of 10, 20, and 30 while the dwell time between pulses are 5CA, 10CA, 15CA, and 20CA. The results demonstrate that the optimum option is 70 (5) 30-30deg “split injection with 70-30% of mass share, dwell of 5CA and with 30 of nozzle divergence” with the best homogeneity of mixture (UI ¼ 0.9742) and peak temperature (Tmax ¼ 2011.58 K) that yield maximum thermo-mechanical exergy amounting to 439 J. In addition, the highest amount of accumulative irreversibility happens for 90 (10) 10e20 deg. It is found that there is a relation between mixture uniformity and accumulative work/heat exergy, whereas a high rate of pressure rise (RPR) contribute to irreversibility rate or exergy destruction in diesel engine, i.e. RPR (80- 20) ¼ 904.67 kPa/deg. More, the results are in agreement with literature reporting that higher in-cylinder temperature (Tmax (70 (5) 30-30deg) ¼ 2011.58 K)) can possibly decrease the accumulative irreversibility.
