Impact of Octane Number and Injection Timing on Autoignition Behaviour of Gasoline and PRF in PPC

Partially premixed combustion (PPC) is one of the advanced combustion concepts that is being actively investigated. A joint experimental and numerical investigations were conducted to explore the effects of octane number and injection timing on the autoignition behaviour with primary reference fuel (PRF) and gasoline fuels under PPC mode in a light-duty DICI engine. In this study, the start of injection (SOI) was selected as the main variable to describe the auto-ignition behaviour of a different fuel. The results revealed that there was a significant difference in autoignition behaviour and combustion characteristics between early and late injection timing. Based on the experimental and numerical results, three difference regimes were defined namely; transition, early SOI PPC and late SOI PPC