Date of Award

January 2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Aeronautics and Astronautics

First Advisor

Steven F Son

Second Advisor

Robert P Lucht

Committee Member 1

Timothee L Pourpoint

Committee Member 2

Lori J Groven


Ammonium perchlorate (AP) is the most commonly used oxidizer in solid rocket propellants due to its availability, high oxygen balance, and combustion characteristics. Models of AP composite propellants have been made since the 1950s and have become highly advanced in recent years. However, experimental data have not kept pace, and the data required to validate models has lagged behind the models themselves. Recently, high-speed OH planar laser-induced fluorescence (PLIF) imaging has been applied to AP composite propellants to determine how microscale propellant flame structure varies with propellant formulation and pressure. Propellants with monomodal AP particle size distributions, changing coarse-to-fine AP particle size ratios, and different sizes and locations of burning rate catalysts have been investigated to determine the effect of propellant formulation on burning rate. It is found that AP particle size, propellant formulation, and pressure have a definite effect on propellant flame structure and burning rate. All propellants with AP particles below about 150 μm display similar flame structures for the pressures investigated (0.1-0.7 MPa). For propellants with AP particles larger than about 150 μm, all propellants burning at 1 atm display jet-like flames above individual coarse AP crystals. If the coarse AP concentration is high enough, group diffusion flames are seen where many coarse AP particles burn with one diffusion flame. At elevated pressures lifted arched diffusion flames are often seen; however, the circumstances under which the lifted flames develop depend on the propellant formulation. Burning rate was seen to increase as the average AP particle size decreased, and vice-versa.