A Critical Analysis of Paraffin-based Fuel Formulations for Hybrid Rocket Propulsion

A wide chemical, thermal, mechanical and ballistic investigation of paraffin-based solid fuels for hybrid propulsion is discussed in the present paper. Different formulations are investigated and characterized, ranging from pure solid paraffin waxes to compositions containing strengthening additives. Thermal properties are studied using a DSC technique to obtain data about the transitions typical of paraffin waxes (solid/solid and solid/liquid) and about the thermal decomposition of the added energetic fillers. Rheological and mechanical properties of the fuels were investigated as well, with a focus on the viscosity of the melted fuels. Firing tests were performed in a lab-scale burner enabling time-resolved regression rate measurement.