With new technologies changing the approach to rocket motor design, engineering researchers at James Cook University have 3D printed fuels and the rockets to test them on.
In the last decade, an exponential increase in the number of rocket launches for sub-orbital scientific missions or for delivering payloads into low Earth orbits led the team to conduct a series of small-scale static fire tests of fused deposition manufacturing hybrid rocket motors. These were designed to explore the performance of a variety of commonly available fused deposition manufacturing materials.
Lecturer in mechanical engineering at JCU, Dr Elsa Antunes, led the study. The team 3D printed fuel grains (solid, plastic-based fuel) for the hybrid rockets using a range of materials.
“We wanted to explore the viability of using commercially available 3D printing materials in the manufacture of hybrid rocket fuel grains," Dr Antunes explained.
"We knew that the common plastic Acrylonitrile Butadiene Styrene (ABS) has shown promise so we decided to test that against six other compounds."
Dr Antunes revealed that the use of hybrid fuelled rockets has become commonplace , with these types of rockets being safer and easier to control.
“3D printing has meant designers have been able to make more complex geometries for rockets and has also opened up the possibility of using novel fuels to power them,” she said.
The researchers 3D printed the rocket and then made a test rig for it at JCU’s Townsville campus. They tested the fuel grain recipes in three-second burns of the motor, before dissecting the fuel cells to analyse their performance.
Dr Antunes said the experiment design was relatively simple as the main objective was to select the best 3D printed fuel grains for a large-scale test as a first step toward a large-scale engine firing campaign and testing of innovative materials.
“There are many new avenues opening up for people working in the field. With new manufacturing techniques such as 3D printing we are able to do things that were just impossible in the past,” she said.