Abstract
A micro-sized hybrid rocket motor was designed, built, and implemented to investigate the comparative combustion behavior of a variety of solid fuel compositions. The goal of this experimental effort is to obtain a relative grading of different solid fuel formulations in terms of regression rate, ignition delay, and radiation emission. Air and oxygen/nitrogen mixtures (up to 50% of oxygen), injected at the head-end of the micromotor, were used as oxidizer. In this phase of investigation, the average chamber pressure was changed in the range of 3.5 to 13 bar, and the volumetric flow rate, 20 to 60 lpm. Quasi-steady regression rates were measured by a proprietary video technique. Ignition delay testing was carried out by exposing solid fuel samples to a controlled laser radiant flux in the range 100 to 300 W/cm(2). Spontaneous radiant energy emission was assessed by means of a microcalorimeter at 7 and 14 bar pressure and 20 and 60 lpm oxidizer flow rate. To validate the effectiveness of the experimental approach, pure HTPB-based fuel was considered in this paper. Some representative data points for aluminized HTPB and paraffin-based fuels are also reported.