Droplet Combustion Characteristics Analysis Based on the Difference in Carbon Chain Length of Saturated Fatty Acid Methyl Ester as Biodiesel Constituents

Abstract

Research on single fatty acid methyl ester compounds is needed to determine the role of molecular structure on biodiesel fuel combustion. Isolated single droplet combustion is the simplest method for understanding complex spray combustion phenomena in compression ignition engines. Analysis of droplet combustion was observed along the heating, evaporation, ignition, and combustion stages. This study investigates the effect of differences in carbon chain length on saturated fatty acid methyl ester compounds as biodiesel constituents on droplet combustion characteristics. Long carbon chain molecules have low luminous flame and higher flame dimension, driven by the natural convection effect of lower gas density from higher temperature of droplet combustion. However, a long carbon chain with higher viscosity and boiling point leads to a longer ignition delay. Higher oxygen content in short carbon chain molecules promotes faster combustion, gives a higher burning rate, and causes the flame dimension to be shorter.