- Author
-
Prentice, J. L.
- Title
- Aluminum Droplet Combustion: Rates and Mechanisms in Wet and Dry Oxidizers.
- Coporate
- Naval Weapons Center, China Lake, CA
- Report
-
NWC TP 5569,
April 1974,
34 p.
- Keywords
-
aluminium
|
droplets
|
combustion
|
oxidizers
|
lasers
|
carbon dioxide
|
water vapors
|
color
|
temperature
|
equations
|
burning rates
- Identifiers
- laser ignition technique; single particle combustion; burning in dry gases; burning in wet gases; ature of combustion debris; fect of water vapor on color temperature; summary of burning geometries; modeling of metal droplet burning; burning rate equations and the significance of the diameter exponent
- Abstract
- This report describes quantitative single aluminum droplet combustion studies in a variety of gaseous oxidizers including CO2 and water vapor. A laser ignition technique was employed which has a demonstrated ability to yield metal droplet burning data of very low scatter. This study reveals that aluminum droplets burn much faster in wet CO2/02 than in any of the other gaseous systems studied (N2/02, Ar/O2). Droplet explosions are found to be characteristic in wet gases and the resultant combustion debris is shown to be both chemically and physically complex. Condensed phase reactions occurring on the droplet surface yield substoichiometric Al-O-C or Al-O-N intermediates prior to the gas-driven droplet explosion. A discussion of droplet burning models is included and the faulty assumptions underpinning them are identified. Based on experimental findings, an outline is given of the direction modeling must take to accurately describe Al droplet combustion.