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Combustion of aluminum nanoparticle agglomerates : From mild oxidation to microexplosion

Tang, Yong; Kong, Chengdong LU ; Zong, Yichen; Li, Shuiqing; Zhuo, Jiankun and Yao, Qiang (2017) In Proceedings of the Combustion Institute2000-01-01+01:00 p.2325-2332
Abstract

While the nano-sized energetic materials are featured with ultra-high energy density, the ubiquitous agglomeration in their combustion is still unexplored. In this paper, the combustion characteristics of aluminum nanoparticle agglomerates in the size range of 4-20μm are investigated on a modified Hencken burner with different temperature (800-1800K) and oxygen concentration (0.5-5.5mol/m3). Due to the heat accumulation effect of the designed porous structures, the nanoparticle agglomerates even maintain the advantages of combustion process of single nanoparticle in terms of a low ignition temperature (∼800K) and a fast energy release rate. Further, the combustion of agglomerates is numerically studied by a newly-developed... (More)

While the nano-sized energetic materials are featured with ultra-high energy density, the ubiquitous agglomeration in their combustion is still unexplored. In this paper, the combustion characteristics of aluminum nanoparticle agglomerates in the size range of 4-20μm are investigated on a modified Hencken burner with different temperature (800-1800K) and oxygen concentration (0.5-5.5mol/m3). Due to the heat accumulation effect of the designed porous structures, the nanoparticle agglomerates even maintain the advantages of combustion process of single nanoparticle in terms of a low ignition temperature (∼800K) and a fast energy release rate. Further, the combustion of agglomerates is numerically studied by a newly-developed model, which accurately predicts both burn time and temperature of agglomerate of the mild combustion process. The microexplosion phenomenon occurs when the oxygen concentration exceeds 3.5mol/m3. Measurements of particle temperature, burn time, emission spectra and morphologies indicate that this explosion is driven by the vaporization of unreacted aluminum core, which results in huge stresses to tear the Al/Al2O3 particle into many smaller, dispersed clusters. Thus a melt/vapor dispersion mechanism (MVDM) based on melt dispersion mechanism is proposed to cover the microexplosion and subsequent accelerated oxidation reactions.

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author
organization
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type
Contribution to journal
publication status
published
subject
keywords
Agglomerates, Al nanoparticles, Melt/vapor dispersion mechanism, Microexplosion
in
Proceedings of the Combustion Institute2000-01-01+01:00
pages
2325 - 2332
publisher
Elsevier
external identifiers
  • scopus:85003683090
  • wos:000397458900077
ISSN
1540-7489
DOI
10.1016/j.proci.2016.06.144
language
English
LU publication?
yes
id
1ba8204b-aaaa-4917-8ace-4412d9a44318
date added to LUP
2017-02-17 14:22:55
date last changed
2018-04-29 04:36:15
@article{1ba8204b-aaaa-4917-8ace-4412d9a44318,
  abstract     = {<p>While the nano-sized energetic materials are featured with ultra-high energy density, the ubiquitous agglomeration in their combustion is still unexplored. In this paper, the combustion characteristics of aluminum nanoparticle agglomerates in the size range of 4-20μm are investigated on a modified Hencken burner with different temperature (800-1800K) and oxygen concentration (0.5-5.5mol/m<sup>3</sup>). Due to the heat accumulation effect of the designed porous structures, the nanoparticle agglomerates even maintain the advantages of combustion process of single nanoparticle in terms of a low ignition temperature (∼800K) and a fast energy release rate. Further, the combustion of agglomerates is numerically studied by a newly-developed model, which accurately predicts both burn time and temperature of agglomerate of the mild combustion process. The microexplosion phenomenon occurs when the oxygen concentration exceeds 3.5mol/m<sup>3</sup>. Measurements of particle temperature, burn time, emission spectra and morphologies indicate that this explosion is driven by the vaporization of unreacted aluminum core, which results in huge stresses to tear the Al/Al<sub>2</sub>O<sub>3</sub> particle into many smaller, dispersed clusters. Thus a melt/vapor dispersion mechanism (MVDM) based on melt dispersion mechanism is proposed to cover the microexplosion and subsequent accelerated oxidation reactions.</p>},
  author       = {Tang, Yong and Kong, Chengdong and Zong, Yichen and Li, Shuiqing and Zhuo, Jiankun and Yao, Qiang},
  issn         = {1540-7489},
  keyword      = {Agglomerates,Al nanoparticles,Melt/vapor dispersion mechanism,Microexplosion},
  language     = {eng},
  pages        = {2325--2332},
  publisher    = {Elsevier},
  series       = {Proceedings of the Combustion Institute2000-01-01+01:00},
  title        = {Combustion of aluminum nanoparticle agglomerates : From mild oxidation to microexplosion},
  url          = {http://dx.doi.org/10.1016/j.proci.2016.06.144},
  year         = {2017},
}