Experiment on the flammability variation of micron-sized aluminum powder depending on combustion environment for burning of aluminum-diluted oxygen
| Autor: | Wando Ki, Woongsup Yoon, Soonho Song, Hyungsuk Lee, Tae-Ho Ko, Kookjin Lee, Kwanyoung Noh |
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| Rok vydání: | 2021 |
| Předmět: |
020301 aerospace & aeronautics
Materials science Superheated steam Oxide Aerospace Engineering 02 engineering and technology Combustion complex mixtures 01 natural sciences law.invention Ignition system chemistry.chemical_compound 0203 mechanical engineering chemistry law 0103 physical sciences Combustor Particle Composite material 010303 astronomy & astrophysics Flammability limit Flammability |
| Zdroj: | Acta Astronautica. 178:51-59 |
| ISSN: | 0094-5765 |
| Popis: | Experimental research was conducted to study the combustion characteristics of clouds composed of micrometer-sized aluminum particles with an oxidizer blend of oxygen and superheated steam. Both ignition and combustion of an aluminum particle are difficult because it is enveloped by an oxide layer that has a high melting point (above 2300 K). To overcome the problem, we induced a particular shape of the combustor that can keep a stable flame of aluminum dust clouds at a lower feeding-rate. The combustion characteristics were examined using a system applied combustor involving a variety of parameters affecting the burning of the dust clouds. Based on these attempts, the aluminum dust clouds had an upper flammability limit above the equivalence ratio (Ф) 1.9 for oxygen diluted by air. Varying the lower limit of flammability, we found, crucially, that the feeding-rate and velocity of the particles are more effective than the equivalence ratio or combustor length. Furthermore, we could confirm the changing of the lower limit from 0.3 to 0.26 because the steam was additionally fed in the combustion of aluminum-oxygen. |
| Databáze: | OpenAIRE |
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