Radiative properties of micron-sized Al/air premixe d flames describ e d by an effective medium core-shell formulation

The goal of this article is to contribute to the knowledge of the phenomenology of the poorly under-stood micron-sized Al/air flames, with the intention of assessing the viability of an energy carrier based on aluminum powders. To this end, the combustion efficiency, temperature, radiative profile, and solid combustion products of a flame prototype have been studied in depth. These fundamental parameters are required to explore the possibilities of recovering the energy released by these flames. In addition, a theoretical model has been established to analyze the radiative properties of the flame, derived for an optically thin collection of independent burning Al particles, each modeled by a core-shell geometry. The structure of the shell, made up of a cloud of alumina nanoparticles, has been modeled with an effective medium following the Maxwell-Garnett relation. This approach can reproduce the experimental results and is thus suggested as a starting point for modeling experiments characterized by strong emission by the nanoparticle cloud.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The goal of this article is to study and understand the poorly understood phenomenology of micron-sized Al/air flames in order to assess their potential as an energy carrier based on aluminum powders. The combustion efficiency, temperature, radiative profile, and solid combustion products of a flame prototype have been thoroughly investigated. A theoretical model has been developed to analyze the radiative properties of the flame, specifically for an optically thin collection of burning Al particles with a core-shell geometry. The model successfully reproduces the experimental results, making it a valuable starting point for future modeling experiments involving strong emission from nanoparticle clouds.