Effects of dense concentrations of aluminum nanoparticles on the evaporation behavior of kerosene droplet at elevated temperatures: The phenomenon of microexplosion
| Autor: | Irfan Javed, Khalid Waheed, Seung Wook Baek |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Fluid Flow and Transfer Processes
Kerosene Materials science Mechanical Engineering General Chemical Engineering technology industry and agriculture Analytical chemistry Evaporation Aerospace Engineering Nanoparticle chemistry.chemical_element Suspension (chemistry) Metal chemistry.chemical_compound Nuclear Energy and Engineering chemistry Aluminium visual_art visual_art.visual_art_medium Silicon carbide Fiber |
| Zdroj: | Experimental Thermal and Fluid Science. 56:33-44 |
| ISSN: | 0894-1777 |
| DOI: | 10.1016/j.expthermflusci.2013.11.006 |
| Popis: | The evaporation behavior of kerosene droplets containing dense concentrations (2.5%, 5.0%, and 7.0% by weight) of aluminum (Al) nanoparticles (NPs) suspended on silicon carbide fiber was studied experimentally over a range of ambient temperatures (400–800 °C) under normal gravity. The evaporation characteristics of the pure and stabilized kerosene droplets were also examined to provide a comparison. The results show that at all of the tested temperatures, the evaporation behavior of suspended kerosene droplets containing dense concentrations of Al NPs was different from that of pure kerosene droplets and exhibited three stages of evaporation; an initial heating up stage, d 2 -law evaporation and then the microexplosion stage. The phenomenon of microexplosion was not observed during the evaporation of pure or stabilized kerosene droplets at the same temperatures. The microexplosions occurred early in the droplet’s lifetime and with a much greater intensity, for either an increase in the ambient temperature or an increase in the NP loading rate. For all of the Al NP suspensions, regardless of the concentration, the evaporation rate remained higher than that of either pure or stabilized kerosene droplets at high temperatures (700–800 °C). The intense microexplosions occurring at these temperatures led to a substantial enhancement in the evaporation rate. However, at lower temperatures (400–500 °C), the delayed onset with lower intensity of the microexplosions was not able to increase the evaporation rate significantly, and it remained similar to that of pure fuel droplets. The maximum increase in the evaporation rate (48.7%) was observed for the 2.5% Al NP suspension droplet at 800 °C. |
| Databáze: | OpenAIRE |
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