Experimental Review of Methods for Performance Enhancement of Paraffin Fueled Hybrid Rocket Motors

While paraffin has the potential to be a high performance fuel for hybrid rockets, sloughing-off of portions of the fuel during the burn, fuel-liner delamination during fabrication, difficult ignition, and the escape of significant amounts of unburned paraffin droplets from the combustion chamber have hindered efforts to demonstrate superior performance in paraffinueled hybrid motors. This work investigates several methods for enhancing the performance of paraffin-based hybrid motors including the use of anti-sloughing baffles in the grain liner, ignition media to ensure repeatable and prompt engine start, improved methods for fuel grain production, and aluminum and potassium nitrate additives. The results of the tests demonstrate modest improvements in anti-sloughing and total impulse, compared to the baseline paraffin fuel grain. Difficulty achieving sufficiently repeatable results with the available commercial motor prevented some of the research goals from being completed but lead to a better understanding of the factors affecting the performance space