Performance enhancing additives for hybrid rockets

A comprehensive assessment of performance additives for a paraffin-based hybrid rocket fuel and preliminary hybrid rocket test firings are presented in this paper. The reason for the selection of paraffin wax fuel binder is discussed as well as the expected performance gain by the addition of energetic materials to the fuel. Al, Mg, LiAlH4 and NBH6 are selected by assessing the thermochemical calculation results and material availability. An experimental study with liquid nitrous oxide oxidizer is concluded which showed Al and LiAlH4 are promising materials for future studies. They increase the c* which in turn increase delivered Isp and decrease the nozzle erosion rate. Also, ammonium borane, which is a promising material due its rich hydrogen content, is studied, but because of the problems in its procurement, extensive testing activity is postponed to a future study.