This paper reports a series of experimental studies performed on sandwich propellants, wherein a matrix lamina of particulate oxidizer and polymeric binder is sandwiched between two ammonium perchlorate (AP) laminae. The catalyst (ferric oxide ) is incorporated in the matrix lamina. The variables are pressure (0.345‐ 6.9 MPa), matrix lamina thickness, catalyst concentration, matrix mixture ratio, types of oxidizer and binder, and the dispersion ability of the catalyst. The combined results indicate that, under the conditions tested, near-surface reactions associated with the particulate AP/binder contact lines on the burning surface assume signie cance in the presence of the catalyst. These reactions are further augmented by the presence of the leading-edge portion of the diffusion e ame above the interface of the matrix and AP laminae.

Mechanism of Burning Rate Enhancement of Composite Solid Propellants by Ferric Oxide

The transition from particle flamelet burning to premixed flame burning of ammonium perchlorate (AP)/hydrocarbon (HC) binder propellants is identified with detachment of the oxidizer/fuel (O/F) flamelet from the stoichiometric tip of the diffusion field over the AP particle. The conditions (pressure, particle area, local stoichiometry) for detachment are revealed by singular regions of the burning rate versus pressure curves for selected bimodal propellants.

The Details of Combustion of Ammonium Perchlorate Propellants: Leading Edge Flame Detachment

An alternative approach to improve burning rate characteristics and processing parameters of composite propellant

Catalytic Nanoparticles in the Combustion of AP/HTPB Composite Solid Propellant. (December 2010) Kevin R. Kreitz, B.S., Texas A&M University Chair of Advisory Committee: Dr. Eric Petersen Presented in this thesis is a study of the effects of nano-sized particles used as a catalytic additive in composite solid propellant. This study was done with titanium oxide (titania)-based particles, but much of the findings and theory are applicable to any metal oxide produced by a similar method. The process required for efficiently producing larger batches of nanoparticle additives was seen to have a significant impact on the effectiveness of the additive to modify the burning rate of composite propellant consisting of ammonium perchlorate (AP) and hydroxyl terminated polybutadiene (HTPB). Specifically, titania was seen to be both an effective and ineffective burning rate modifier depending on how the nanoparticle additive was dried and subsequently heat treated. Nanoadditives were produced by various synthesis methods and tested in composite propellant consisting of 80% AP. Processability and scale-up effects are examined in selecting ideal synthesis methods of nanoscale titanium oxide for use as a burning rate modifier in composite propellant. Sintering of spray-dried additive agglomerates during the heat-treating process was shown to make the agglomerates difficult to break up during mixing and hinder the dispersion of the additive in the

Catalytic Nanoparticle Additives in the Combustion of AP/HTPB Composite Solid Propellant

Combustion of propellants with ammonium dinitramide

: The mechanism of burning rate enhancement of propellants by catalysts is examined by tests on ammonium perchlorate (AP) sandwiches and bimodal AP propellants Burning rates were measured from motion pictures, and samples from quench tests were examined in the scanning electron microscope The results indicated that effective catalysis depends on concentration of the catalyst on the binder surface so as to permit adequate permitting the oxidizer-fuel flame to stand closer to the surface

E. W. Price

Papers

Mechanism of Burning Rate Enhancement by Ferric Oxide