Closed Chamber Burning Characteristics of New VHBR (Very High Burning Rate) Formulations

摘要

Combustion studies were carried out on VHBR propellants in order to determine formulation and fabrication parameters that control the burning characteristics of these compounds. Formulation parameters such as type of fuel, oxidizer, type and percent of binder, oxidizer/binder ration and percent of theoretical maximum density were varied and the effects on combustion were studied using both a closed chamber and an optically transparent bomb. Although numerous facets of the combustion mechanisms remain unclear, the following picture has emerged for the specific formulations studied. The first phase of combustion is a relatively slow porous burning that proceeds down throughout the sample. The original form of the sample remains, although the residue is porous and is filled with hot combustion products. Depending on the composition, percent theoretical density and sample confinement, a transition to a very rapid combustion takes place throughout the entire sample, accompanied by some deconsolidation. For some conditions (composition or confinement) this second phase does not occur. The transition pressure to and the velocity of the second phase varies with the formulation parameters. The details of these results are discussed in the remainder of the paper.