Combustion of HTPB Based Solid Fuels Containing Metals and Metal Hydrides with Nitrous Oxide

An experimental investigation of the combustion characteristics of HTPB‐based solid fuels containing aluminum and aluminum hydride has been conducted. Aluminum is commonly used as a fuel supplement in solid rocket propellants because of its ability to increase the specific impulse of a propellant. Similarly, aluminum hydride, or alane, is another attractive fuel supplement because it can significantly (∼7–8 %) increase specific impulse even beyond that of aluminum. In this study, the regression rates of a baseline fuel (pure HTPB) were compared with that of fuels containing either aluminum or alane as additives using a counterflow combustion experiment with nitrous oxide (N 2 O) as the oxidizer. The additives were investigated in concentrations of 10, 20, and 40 % by weight of the fuels. The addition of aluminum at all loadings resullted in a decrease in the regression rate relative to the baseline, whereas the addition of alane resulted in at worst similar regression rates and at best (highest loading) approximately a 20 % increase in regression rate. The decomposition behavior of selected fuels was analyzed using traditional thermal analysis techniques; thermal gravimetric analysis and differential scanning calorimetry