On the optimization of GAP-based ducted rocket fuels from gas generator exhaust characterization

Abstract

The performance of a ducted rocket motor depends greatly on the composition of the exhaust products from its solid fuel gas generator. A series of experiments has been conducted to characterize the exhaust of GAP/carbon gas generator fuels as a function of pressure and grain formulation. Fuel samples were ignited in a closed vessel and gases collected for further analysis using gas chromatography. The major gaseous components identified in the exhaust stream were nitrogen, hydrogen and carbon monoxide while the condensed phase was found to be a carbon-rich soot. The relative amounts of each major component depended greatly on the chamber pressure and the precise formulation used, thus providing a simple means of optimizing the exhaust composition to maximize the performance of the ducted rocket propulsion systems.