Micro-explosion of droplets containing liquids with different viscosity, interfacial and surface tension

• Published in: Chemical engineering research & design 2020-06, Vol.158, p.129-147
• Main Authors: Antonov, Dmitrii V., Kuznetsov, Geniy V., Strizhak, Pavel A., Fedorenko, Roman M.
• Format: Article
• Language: English
• Subjects: Atomizing; Breakup; Chemical reactions; Combustion chambers; Droplets; Emulsified fuel; Evaporation; Heating; Interfacial tension; Micro-explosion; Puffing; Spraying; Studies; Surface tension; Temperature effects; Viscosity
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2020.03.029

[Display omitted] •Small child droplets can be obtained by reducing the viscosity and surface tension.•The higher the viscosity and surface tension, the higher the breakup delay time.•The lower the interfacial tension, the higher number of heterogenic child droplets.•Micro-explosion delay time is minimum with the minimum emulsifier content.•The boundaries between breakup regimes depend of liquid and gas temperatures. Micro-explosion and puffing of multi-component slurry and emulsified fuel droplets can provide a several-fold increase in the evaporation and chemical reaction surface area. As a result, micro-explosion and puffing shorten the heating, evaporation, and ignition time of fuel compositions, improve the efficiency of their combustion, reduce fuel consumption, and provide its smooth spraying in combustion chambers. There are still no thorough studies on how the viscosity as well as surface and interfacial tension of emulsified fuels affect the integral characteristics of micro-explosive breakup of droplets under intense heating. In certain ranges of temperatures and component concentrations, there may be synergistic effects of these fuel characteristics on the threshold conditions and outcomes of micro-explosive droplet atomization. Such synergistic effects can make the secondary atomization of fuel droplets much more effective. In this research, we experimentally determine the heating times until breakup of relatively large emulsion droplets, the size and velocity distributions of newly formed child droplets with varying heating temperature, initial size of parent droplets, as well as component type and concentration. The results of this research are important for developing the current micro-explosion models and creating new, accounting for the breakup mechanisms and outcomes.