Experimental investigation into particulate size and number distribution from a spark ignition engine: in-cylinder combustion and transient events

The work presented here had two main aims: first, it investigated the relationship between in-cylinder combustion performance and particulate size distribution and number count; second, it examined the possibility of reconstructing transient events using steady state test data relating to particulate size distribution and number count. It identified a strong correlation between the geometric mean diameter (GMD) of the engine-out particulate matter and the rate of burning during the early stage of combustion. In addition, it identified correlations between the coefficient of variance for 50 per cent mass fraction burned and the coefficient of variance for particulate GMD. The tests relating to transient events identified that steady state data can be used to reconstruct acceleration events, but not deceleration events. The methodology followed to obtain these findings is detailed in this paper.