Effect of polymorphic phase transformations in alumina layer on ignition of aluminium particles

Research output: Contribution to journalArticlepeer-review

240 Scopus citations

Abstract

The mechanism of aluminium oxidation is quantified and a simplified ignition model is developed. The model describes ignition of an aluminium particle inserted in a hot oxygenated gas environment: a scenario similar to the particle ignition in a reflected shock in a shock tube experiment. The model treats heterogeneous oxidation as an exothermic process leading to ignition. The ignition is assumed to occur when the particle's temperature exceeds the alumina melting point. The model analyses processes of simultaneous growth and phase transformations in the oxide scale. Kinetic parameters for both direct oxidative growth and phase transformations are determined from thermal analysis. Additional assumptions about oxidation rates are made to account for discontinuities produced in the oxide scale as a result of increase in its density caused by the polymorphic phase changes. The model predicts that particles of different sizes ignite at different environment temperatures. Generally, finer particles ignite at lower temperatures. The model consistently interprets a wide range of the previously published experimental data describing aluminium ignition.

Original languageEnglish (US)
Pages (from-to)603-623
Number of pages21
JournalCombustion Theory and Modelling
Volume10
Issue number4
DOIs
StatePublished - Aug 2006

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Modeling and Simulation
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Physics and Astronomy(all)

Keywords

  • Aluminium
  • Ignition temperature
  • Oxidation kinetics

Fingerprint

Dive into the research topics of 'Effect of polymorphic phase transformations in alumina layer on ignition of aluminium particles'. Together they form a unique fingerprint.

Cite this