Comprehending the influence of the particle size and stoichiometry on Al/CuO thermite combustion in close bomb: a theoretical study

Autor: Emilian Tichtchenko, Benoit Bedat, Olivier Simonin, Ludovic Glavier, David Gauchard, Alain Esteve, Carole Rossi
Přispěvatelé: Équipe Nano-ingénierie et intégration des oxydes métalliques et de leurs interfaces (LAAS-NEO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), ArianeGroup, Service Informatique : Développement, Exploitation et Assistance (LAAS-IDEA)
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Propellants, Explosives, Pyrotechnics
Propellants, Explosives, Pyrotechnics, 2023, pp.e202200334. ⟨10.1002/prep.202200334⟩
ISSN: 0721-3115
1521-4087
DOI: 10.1002/prep.202200334⟩
Popis: International audience; The paper is a theoretical exploration of complex Al/CuO thermite combustion processes, using a zero-dimensional (0D) model which integrates both condensed phase and gas phase reactions, and considers all thermodynamic stable molecular or atomic species identified during the Al+CuO reaction. We found that the particle size mainly influences the reaction kinetics and pressure development. Thermite with nano-sized particles (nanothermites) burns ~10 times faster than the same thermite with micron-sized particles (microthermites). This is due to the fact that the thermite reaction occurs mainly in condensed phase, i.e. in the melted Al phase, as all gaseous oxygens released by the CuO decomposition are spontaneously absorbed on the huge specific surface area of metallic Al. As a consequence, the pressure development in nanothermites follows the thermite chemical reaction, the gas phase is mostly composed of a metal vapor (mostly Cu and Al), Al suboxides, but is free of molecular oxygen. In contrast, when dealing with microthermites, an oxygen pressure peak occurs prior to the thermite reaction due to the gaseous O2 released by the early CuO decomposition, that cannot be absorbed on the Al particles surface in real time. The powder stoichiometry greatly impacts the final pressure. Al lean thermites generate a higher final pressure (× 3) than stoichiometric and Al rich mixtures, due to unreacted gaseous oxygen which remains in the gas phase after the full consumption of the metallic Al.
Databáze: OpenAIRE
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