Date of Award
Summer 7-21-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Mechanical Engineering
First Advisor
Somesh Roy
Second Advisor
Adam Dempsey
Third Advisor
Cris Ababei
Abstract
Soot formation remains one of the least understood phenomena in combustion science, posing significant challenges due to its complex physicochemical nature and considerable environmental and health impacts. This dissertation presents a comprehensive molecular-level investigation into the fundamental mechanisms governing soot inception, particle growth, and morphological evolution through state-of-the-art reactive molecular dynamics (RMD) simulations of acetylene pyrolysis. A novel computational analysis utility, Molecular Arrangement and Fringe Identification and Analysis from Molecular Dynamics (MAFIA-MD), was developed to accurately characterize soot particle formation, providing detailed insights into chemical composition, internal structure, and surface characteristics. Critical physicochemical markers defining the boundary between gas-phase species and particulate soot were rigorously identified, including specific primary particle mass and number of carbon atoms. Extensive analyses of internal structural evolution revealed essential insights into particle density variations, radial distribution of internal features, and structural complexity during soot nucleation and growth. Furthermore, detailed characterization of soot particle pore structures and surface morphology established quantitative relationships among morphological features, fractal dimensions, and particle reactivity, significantly enhancing predictive capabilities of engineering scale models. This dissertation effectively addresses critical gaps in current knowledge by providing robust methodologies and extensive molecular-level insights that substantially advance our understanding of soot formation processes. The outcomes of this research offer essential contributions towards refining predictive combustion models and developing targeted strategies for emissions control, thereby supporting cleaner combustion technologies, improved public health, and environmental sustainability.