MK1 Hybrid Engine

May 2022 - August 2022

Over the summer of 2022, our small team of 4 designed, built, and tested a proprietary paraffin wax and nitrous oxide hybrid engine.

My Contributions

  1. Gyroid ABS infill design specifications.

  2. Plumbing system mounting and pipe diameter calculations.

  3. Test stand design and construction (not including load cell assembly).

  4. Load cell assembly CAD.

Test Stand Failures and Challenges:

  • System max tilt between 20-30 degrees.

  • System slide approx 30-40cm.

  • Rigid plumbing shifted from its original position.

  • 3 days to design and construct the system.

Lessons Learned:

  • The gyroid ABS infill worked really well to keep the paraffin wax from melting and blasting away, contributing to smooth combustion.

  • Nitrous must flow slower than 10m/s entering the injector to prevent water hammering. I determined the optimal pipe diameters to ensure the flow velocity of nitrous would not produce water hammering effects while still encouraging quenching.

  • Proper static analysis of the test stand would reveal the testing infrastructure was too light and would torque.

  • The engine produced more than double the predicted thrust. As a precaution, future test assemblies will be built with larger safety factors.

Test Stand Successes:

  • Load cell assembly functioned as designed.

  • Plumbing remained operational and rigid.

  • The scaffolding did not buckle, flex, or shear.