Systematic experimental study of nanoparticle-mediated evaporation, boiling, and fragmentation of bicomponent droplets

An experimental investigation was conducted at atmospheric pressure to examine the vaporization behavior of bicomponent droplets suspended on a quartz fiber and doped with 0.1–0.5 wt% Al₂O₃ nanoparticles (NPs) over an ambient temperature range of 200–500°C. Infrared thermography and high-speed imaging were employed to characterize the apparent temperature evolution, vaporization rate, bubble dynamics, and fragmentation behavior of the droplets. The results show that, across all tested temperatures, bicomponent droplets containing Al₂O₃ NPs exhibit vaporization behaviors distinct from those of base droplets. The presence of nanoparticles is associated with a faster heating process but a reduced effective evaporation area. As a result, evaporation is suppressed at relatively high nanoparticle concentrations but promoted at lower concentrations. In the case of droplet boiling, those containing Al₂O₃ NPs exhibit a shorter boiling delay time and a larger boiling duration fraction than base droplets. The observed boiling behavior is consistent with an increased availability of heterogeneous nucleation sites and enhanced internal heat transport. Additionally, nanoparticle-laden droplets tend to exhibit smaller bubble sizes and higher number densities during boiling. Finally, the addition of nanoparticles is found to modify the fragmentation mode of the droplet, shifting from infrequent, high-intensity micro-explosions toward more frequent, lower-intensity jetting events as the nanoparticle concentration increases. These results provide experimental evidence of the influence of Al₂O₃ NPs on the evaporation, boiling, and fragmentation behaviors of multicomponent fuel droplets, offering insights relevant to the development and validation of nanofuel vaporization models.