Abstract
The operating range in premixed diesel combustion is limited by rapid combustion at maximum loads and unstable ignition at minimum loads, both affected by ignition delays and ignition timings depending on fuel ignitability. To analyze the correlation between ignition delays and common fuel ignitability factors represented by cetane number or octane number, fuels with various ignitability factors were examined at an early injection timing (30°CA BTDC) and a low intake oxygen content. The ignitability factors correlated moderately with ignition delays, with notable irregular fluctuations. The operating range in premixed diesel combustion depended most strongly on the actual ignition delay.
