Design, Simulation, and Testing of an ABS/GOX Hybrid Rocket Engine

Abstract

Hybrid rocket engines are safer, cheaper, and less complex than liquid rocket engines, while providing many of their benefits, such as variable thrust and longer burn times. Solid motors are simpler than hybrids, but do not offer for the controllability of a hybrid. For these reasons, hybrid rocket engines are an ideal platform for investigating rocket thrust. This research project encompassed the design, simulation, and testing of such a rocket engine.

The engine used 3D printed ABS (acrylonitrile butadiene styrene) plastic as the solid fuel, and gaseous oxygen (GOX) as the oxidizer. ABS plastic is readily available and has the material properties that allows for the printing of complex fuel geometries without the hassle of curing resin based fuel grains. GOX is cheap, non-toxic, and much safer than liquid oxygen. The engine was built into a mobile test stand that can be used by future students to further explore rocket propulsion.

In addition to the physical engine, a MATLAB simulation of the rocket was developed and made publicly available, to allow for iterating on engine designs much more efficiently than actually building new components for each iteration.

The engine was successfully tested seven times and produced up to 650 Ns of total impulse. The simulation produced thrust curves that matched measured thrust within 17%. This represented a successful capability demonstration of what will undoubtedly be an ideal testing platform for students in the years to come.