Small-Scale Static Fire Tests of 3D Printing Hybrid Rocket Fuel Grains Produced from Different Materials

Abstract

The last decade has seen an almost exponential increase in the number of rocket launches for sounding missions or for delivering payloads into low Earth orbits. The emergence of new technologies like rapid prototyping, including 3D printing, is changing the approach to rocket motor design. This project conducted a series of small-scale static fire tests of fused deposition manufacturing hybrid rocket motors that were designed to explore the performance of a variety of commonly available fused deposition manufacturing materials. These materials included acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid (PLA), polypropylene, polyethylene terephthalate glycol, Nylon, and AL (PLA with aluminum particles). To test the performance of small-scale fuel grains, a modular apparatus with a range of sensors fitted to it was designed and manufactured. The small-scale testing performed static burns on two fuel grains of each material with initial dimensions of 100 mm long and 20 mm in diameter with a 6 mm straight circular combustion port. The focus of this study was mainly on the regression rates of each material of fuel grains. Acrylonitrile styrene acrylate and Nylon showed the highest regression rates, while the polyethylene terephthalate glycol regression rates were relatively poor. Also, the acrylonitrile butadiene styrene and acrylonitrile styrene acrylate demonstrating relatively high regression rates when compared to existing hybrid fuels like hydroxyl-terminated polybutadiene.