Emissions characteristics of a new low-NO, diesel combustion concept termed
MULDIC (MULtiple stage DIesel Combustion), were examined under high load c
onditions. In conventional diesel combustion, a near-stoichiometric mixture
is formed during the ignition delay, which results in a large amount of NO
x generated during the ensuing premixed combustion. Moreover, there is also
a region of stoichiometric mixture formed when fuel mixes with air in diff
usion combustion, where NOx is also produced. In MULDIC, premixed combustio
n and diffusion combustion are separated in time, and optimized independent
ly. As a result, NOx emissions from MULDIC were reduced to less than half t
he values typical of conventional diesel combustion, at the same fuel consu
mption.