Spray characterization of ethanol and saturated biodiesels of different carbon chain lengths

This paper examines the flame appearance, non-reacting and reacting spray of ethanol, a short and a medium carbon chain length biodiesel in a co-flow burner using digital images and Phase Doppler Anemometer (PDA). The effects of fuel chemical structures on flame luminous location, dispersion level, number droplet distribution, and droplet velocity decay rate are investigated. Some differences in luminous locations in the flames of these fuels are observed. The medium chain length biodiesel shows the lowest luminous locations in all flame conditions; at the dense spray zone, the short chain length biofuel has the highest luminous locations while this belongs to ethanol at the dilute spray zone. Non-reacting spray dispersion levels of the medium chain length biofuel are higher compared to those of its counterparts. Velocity decay rates of non-reacting droplets are much higher with respect to those of reacting ones, especially at downstream locations.