Burning dynamics of graphene oxide doped diesel droplets

Burning dynamics of graphene oxide (GO) doped diesel droplets are investigated experimentally. The experiments are performed for diesel droplets doped with 0, 0.001, 0.005, 0.01, and 0.02% by mass of GO. A high-speed shadowgraphy technique, with imaging acquisition frequency and resolution of 2000 Hz and 21 μm, is employed. All tested droplets feature atomization, which starts at about 20 to 30% of the droplet lifetime. The onset of atomization advances with increasing the doping concentration. Prior to atomization, a shell of aggregates is formed immediately after ignition and breaks down as a result of recirculatory flow inside the droplets. Once atomization starts, several bubbles are formed inside the droplets and their surfaces become significantly corrugated. Analysis of the shadowgraphy images shows that the frequency of the bubble formation and the intensity of the droplet surface corrugations are positively and negatively related to the doping concentration, respectively. Overall, the results show that the addition of GO to diesel increases the droplet burning rate, which is of interest for industrial applications.