THERMAL SCIENCE

International Scientific Journal

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Tingyu Zhao

,

Junhua Fang

,

Zhen Huang

THE EVOLUTION OF SOOT MORPHOLOGY FOR THE MATURATION OF NASCENT PARTICLE IN A TURBULENT LIFTED JET FLAME

ABSTRACT
In order to understand the soot formation in Diesel engine, a turbulent jet flame is used to simulate the combustion in the cylinder. The experimental study is performed to investigate the evolution of soot morphology for the maturation of nascent particle in a turbulent lifted jet flame fueled by n-heptane/toluene mixtures. An ultrasonic atomizer is used to evenly spread the fuel droplets to acquire single primary particles. Transmission electron microscopy is used to study the morphology of the particle sampled from the flame at different heights. Small soot aggregates are acquired from all the samples. Particle maturation such as agglomeration is accelerated under a high temperature by comparing the particle morphology sampled on the centerline and the wings of the flame. The precursors of nascent particles are depicted as dark nucleation dispersed to semitransparent polycyclic aromatic hydrocarbons. The nanostructure of nascent particles transforms from an amorphous state to an onion structure with the maturation of particles. Surface growth initially dominates the maturation of nascent particles in the direction of outside to inside for single particles. Agglomeration begins to emerge with the increased probability of collision at the end of maturation. Surface growth and agglomeration increase the mean particle diameter as the flame height increases. The oxidability of particles that undergo surface growth and agglomeration notably increases. The structure of nascent particles is inclined to be ordered and the mean particle diameter decreases with oxidation dominating the combustion reaction.
KEYWORDS
soot morphology, transmission electron microscopy, nascent particles, jet flame
PAPER SUBMITTED: 2021-11-16
PAPER REVISED: 2022-03-30
PAPER ACCEPTED: 2022-04-04
PUBLISHED ONLINE: 2022-05-22
DOI REFERENCE: https://doi.org/10.2298/TSCI211116057Z
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 6, PAGES [4595 - 4605]
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The evolution of soot morphology for the maturation of nascent particle in a turbulent lifted jet flame

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence