Liquefying Fuel Combustion in a Lab-scale Vortex Flow Pancake Hybrid Rocket Engine

The combustion behavior of paraffin-based blends is investigated by a lab-scale vortex flow pancake motor (VFP). A complete pre-burning characterization for different paraffin-based fuel formulations is performed. The tested compositions are based on a micro-crystalline paraffin wax (W1), possibly blended with a styrene-based reinforcing polymer (SEBS-MA). Liquid paraffin (LP) is considered as an additional fuel ingredient for mechanical properties tailoring. The pre-burning characterization of the fuels includes thermal behavior investigation, rheological, tensile and compression analyses. In this preliminary investigation, 12 combustion tests are performed with quasisteady operating conditions. The main observable of interest is the solid fuel regression rate. Effects of the vortex flow combustion on the combustion efficiency are assessed by the characteristic velocity efficiency of the lab-scale system. The pre-burning characterization proves that SEBS-MA is a good candidate for improving the mechanical and thermal characteristics for the blends. LP had a significant impact on decreasing the viscosity of the blends.