Effect of pilot injection on DMDF combustion characteristic and gaseous emissions were analyzed.
Regulated and unregulated gaseous emissions from the engine with DMDF system were examined.
Compared with single injection, pilot injection strategy could reduce most of gaseous emissions.
Increasing pilot quantity could reduce HC, CO and most of unregulated emissions of DMDF engine.
Advancing pilot injection timing caused an increase in some unregulated emissions on M50 mode.