Characterization of the Morphology and Nanostructure of the Soot Particles Produced within Transient Diesel Reacting Jet Flame by Using Thermophoretic Sampling Technique

Abstract

In this work, thermophoretic sampling experiments are carried out in a constant volume combustion chamber (CVCC) accompanied by the subsequent high-resolution transmission electron microscopy (HRTEM) imaging to investigate the morphology, nanostructure, and size of soot particles directly sampled within the reacting diesel jet spray flame under ambient conditions close to practical engine combustion. The experiments are performed with different fuel injection masses to examine the variation of the morphological and nanostructural parameters of soot primary particles and aggregates with the fuel injection quantity, Qs. The results show the particles sampled in the cases with low fuel injection quantity (Qs) have a fraction of separately existing small primary particles and small aggregates made up of only several primary particles. As the fuel injection mass is further increased, the number of soot particles increase but the projection area becomes smaller. The fractal dimension of the sampled aggregates i...