Coupled sputtering and combustion dynamics of diverse fuel types

Abstract

This study presents a comprehensive computational investigation of the sputtering and combustion dynamics of biodiesel and fossil diesel fuel droplets in turbulent gas flows. Advanced computational modeling and the CHEMKIN chemical kinetics framework were employed to analyze the thermophysical and chemical processes of fuel atomization, ignition, and flame propagation under varying oxidizer temperatures. The results indicate that biodiesel droplets exhibit higher mobility, enhanced mixing with the oxidizer, and more uniform heating, resulting in near-complete combustion and higher local temperatures compared to fossil diesel fuel. Soot formation during biodiesel combustion was notably lower, while carbon monoxide emissions were significantly reduced, demonstrating more efficient and cleaner combustion. Analysis of the Sauter mean diameter (SMD) highlighted improved droplet dispersion and atomization quality for biodiesel, facilitating optimized injector design and fuelair mixing. Heat flux visualization revealed stronger convective energy transfer in biodiesel flames, and flame front dynamics confirmed that biodiesel can be used in conventional internal combustion engines without modification. Overall, these findings highlight biodiesel as a sustainable, low-emission alternative to fossil diesel fuel, supporting the development of energy-efficient technologies and the transition toward cleaner, renewable fuels.