Dynamic mechanism of biodiesel-ethanol-graphene droplets during micro-explosion and puffing: Droplet evaporation, distribution and velocity characteristics

Adding graphene to biodiesel and ethanol blends can significantly improve the combustion efficiency, which can significantly reduce pollutant emissions when applied to alternative engine fuels. The study of the droplet dynamic properties of biodiesel-ethanol-graphene blends can help to aid in a deeper understanding of the properties of the fuel, which in turn can provide a theoretical basis for the application of the fuel. In this paper, a modified tube furnace experimental platform was used to investigate the evaporation, micro-explosion, and dynamic properties of parent and child droplets of biodiesel-ethanol-graphene. The micro-explosion and dynamics mechanisms of the parent droplets and child droplets of the blended fuel were further investigated in terms of graphene content, ambient temperature and biodiesel/ethanol blend proportion. During the research, three modes of bubble growth in droplet were proposed, the number and velocity of child droplets and the intensity of micro-explosion were found to have a positive correlation trend. It is found that BD50E50(1%G) droplets show high micro-explosion effect and evaporation rate, and can be considered as a sustainable alternative fuel for airlines or oil companies. The movement law of mixed droplets is analyzed, and the internal conditions and external characterization parameters of micro-explosion are summarized. [Display omitted] •The parent droplet expansion stage has three volumetric growth modes.•The micro-explosion intensity grows with the increase of temperature.•The addition of graphene improves the heat transfer.•Adding graphene in a certain range can improve the micro-explosion intensity.•The droplet velocity were determined by air pressure and the order.