Numerical investigation of dual-fuel engine improvements using split injection natural gas coupled with diesel injection timings at low load condition

The dual-fuel engine improvements using natural gas and diesel fuels are attractively conducted in recent years to overcome the emissions issues with high engine performance. Unfortunately, the dual-fuel engine has low combustion characteristics and forms high HC emissions at low load conditions. This study optimizes engine combustion and emissions with some diesel injection configurations with split injection natural gas strategies. However, the natural gas split injection is used in several dwelling times with proportional split injection ratios. Numerical works are conducted for this study with various validation data. The results found that long dwelling time with retarding diesel injection timing performs the optimum condition for the combustion characteristics. The ITE is higher than the other dwelling times with lower peak cylinder pressure. HC and CO emissions are improved with slightly higher NOx emissions with fewer differences than the other dwelling times.