Radiative heat transfer from aluminum oxide in solid propellant flames

The radiative heat transfer in aluminized propellant flames was determined. Liquid aluminum oxide (Al$\sb2$O$\sb3$) particles, produced from the distributed combustion of aluminum droplets, dominated the optical characteristics of aluminized propellant flames. A laser scattering and extinction technique was developed to determine the optical properties of liquid Al$\sb2$O$\sb3$ in the propellant flames at two wavelengths. Optical properties consisted of the real and imaginary parts of the complex index of refraction (n = n $-$ ik) and the parameters describing the particle size distribution. The optical properties were obtained by an implicit method involving the Mie scattering theory and a solution of the radiative transfer equation. Equations predicting the complex index of refraction for liquid Al$\sb2$O$\sb3$ as a function of wavelength and temperature were obtained by performing a dispersion analysis. A one-dimensional distributed combustion model was developed to predict the two-phase reacting flow-field above the burning propellant surface. The primary purpose of the distributed combustion analysis was to obtain oxide temperature and concentration profiles, and aluminum diameter and concentration profiles. The results of the distributed combustion model were used as input to the decoupled radiation model. The radiation model consisted of the solution of the radiative transfer equation for the flow-field above a burning aluminized propellant. The radiative transfer equation was solved by both a two-flux method and a diffusion approximation. The two-flux method was used for analyzing the optically thin medium near the surface of the propellant. At distances farther from the propellant surface, where the medium became optically thick due to the Al$\sb2$O$\sb3$ smoke particles, the diffusion approximation was used. Both wavelength and temperature dependence of the complex index of refraction were taken into account throughout the radiation analysis.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Parry, David Lloyd

Contributors dc:contributor

• Brewster, M. Quinn

• Engineering, Mechanical

Statement dc:rights

• Copyright 1989 Parry, David Lloyd

Language dc:language

eng

Identifier

AAI8924917
(UMI)AAI8924917

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20763