Resumen
Using high-speed video recording, we establish the following regimes of hydrodynamic interaction of a biodiesel micro-emulsion fuel droplet with a heated wall: deposition (including drop spreading and receding), drop hydrodynamic breakup, and rebound. Collision regime maps are plotted using a set of dimensionless criteria: Weber number We = 470?1260, Ohnesorge number Oh = 0.146?0.192, and Reynolds number Re = 25?198. The scenarios of droplet hydrodynamic disintegration are studied for transient and film boiling. We also estimate the disintegration characteristics of a biodiesel micro-emulsion droplet (mean diameter of child droplets, their number, and evaporation surface area increase due to breakup). The study establishes the effect of water proportion on the micro-emulsion composition (8?16 vol.%), heating temperature (300?500 °C), droplet size (1.8?2.8 mm), droplet velocity (3?4 m/s), rheological properties of the examined compositions, and emulsifier concentration (10.45 vol.% and 20 vol.%) on the recorded characteristics. The results show that the initial liquid surface area can be increased 2?19 times. The paper analyzes ways to control the process. The hydrodynamic disintegration characteristics of a biodiesel micro-emulsion fuel droplet are compared using 2D and 3D recording.