Experimental research focus on the emission characteristics of a diesel engine employed a new combustion system-double swirl
combustion system (DSCS) is carried out. The influence of spray angle on diesel emission characteristics with DSCS is analyzed
by experimental and numerical method. Main emissions such as particulate matters (PM) and nitrogen oxidants (NOx) are
measured in diesel engine with DSCS and the original engine. Also, fuel consumption, combustion pressure, heat release rate are
compared between two systems. The tests results indicate that employing DSCS can acquire a remarkable reduction of PM
(within the range of 7~47%) with lowered fuel consumption (0.75~3.05%). The reason of which is accounted via analyzing the
in-cylinder combustion course. Furthermore, the experimental research shows that the spray angle is a significant factor for
performance of DSCS since it determined the ratio of fuel distributed between inner and outer chamber. The related particulars
are analyzed by numerical method.