Études expérimentales et modélisation de la combustion des nuages de particules micrométriques et nanométriques d'aluminium.

Abstract : The numerous new projects for ambitious space missions have revived the interest for the investigation of solid-state rocket engines. Among others, aluminum particles are one of the main compounds of a solid-propellant propulsion unit. However, incomplete combustion and agglomerate formation are remaining issues. A proposed solution to avoid them is to use nanometric particles instead of commonly employed micrometric-size particles.
The objective of this work was to experimentally characterize the combustion in air of both micrometric and nanometric aluminum particle clouds for strong richnesses and under standard conditions for temperature and pressure. In order to achieve our goals, a specific test bench was developed and various diagnostic techniques were used to gain knowledge in the physical mechanisms at work during combustion of tiny aluminum particles. Moreover, computer simulations were carried out to support experimental outcomes. The study reveals that the speed of flame increases with the particle concentration. For an identical concentration, combustion propagates faster throughout clouds of nano-particles. The temperature of the gas phase and the condensed phase are lower for nano-particle clouds than for micro-particle clouds. A physical model based on fitted parameters allows to obtain combustion times in good agreement with experimental outcomes. Two power-laws relations in which the combustion time varies as either D0,25 or D0,49 are derived when considering nanometric particles that are not agglutinated.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00347592
Contributor : Pablo Escot Bocanegra <>
Submitted on : Tuesday, December 16, 2008 - 11:39:31 AM
Last modification on : Wednesday, March 20, 2019 - 1:20:20 AM
Long-term archiving on : Tuesday, June 8, 2010 - 5:22:07 PM

Identifiers

  • HAL Id : tel-00347592, version 1

Citation

Pablo Escot Bocanegra. Études expérimentales et modélisation de la combustion des nuages de particules micrométriques et nanométriques d'aluminium.. Energie électrique. Université d'Orléans, 2007. Français. ⟨tel-00347592⟩

Share

Metrics

Record views

563

Files downloads

2504