S.H.E.A.R Audacity

Team Lead, Lead Systems Engineer, Mechanical Engineer - 2025 to present

What Is S.H.E.A.R Audacity

S.H.E.A.R Audacity is a 7 foot tall 4 inch diameter vehicle designed to break the world record for amateur liquid rocketry. Developed by a group of 6 OSU students as an independent project, funding it ourselves. We wanted to show the power of rapid iterative design using N2O IPA liquid engines.

I lead the team to start development of the initial 4KN liquid engine called "Triple 4", with the name referencing the 4 inch diameter, the 4KN operating thrust, and the 4 oxidizer to fuel ratio. Originally this engine would be the solution to rising ammonium perchlorate cost, replacing the solid propulsion system on the Oregon State University Student Competition Rocketry Team. Unfortunately, with the pre-existing liquid engine team already established, there were concerns about competition between the teams from leadership. The decision was made to go independent, and prove the technology ourselves while beating a world record.

Using programs like RPA, Solidiworks Flow Sim, StarCCM+, Ansys, (yes we used three CFD softwares) we have been able to simulate performance of the engine, ensuring that flow does not phase change and that efficiency is retained. Working closely with our propulsion lead, we have designed an extremely simple but extremely robust bi-propellant rocket engine.

The engine utilizes technology derived from commercial hybrid rocket systems. As it is a nitrous oxide engine, the vapor pressure is so low that the N2O becomes the pressuring for the engine. This in turn pushes down not only on the remaining liquid N2O, but also a piston, allowing for the fuel, IPA, to flow into the combustion chamber.

Compared to other amateur liquid rockets, the fill procedure is extremely simple. Instead of a quick disconnect that will often get stuck due to cooling, we utilize burn away tubing to fill the nitrous oxide. During the fill process, the central brass fitting has pressure acting on it, forcing the check valve into place, preventing the flow of N2O or IPA into the injection elements. To launch, a small solid fuel grain is lit in the combustion chamber. This melts the tube allowing for pressure to drop and in turn lowering the check valve. As propellants flow they ignite on this solid grain and burn away the tubing.

Soon after engine development, the vehicle, SHEAR Audacity, was further fleshed out with simulated performance putting the vehicle at 57,000 feet, allowing us to beat the world record for altitude from an amateur bi-propellant liquid rocket. Vehicle CAD and final design is sitting at 80% complete, awaiting parts to arrive and a full duration static fire from "Triple 4".

Full vehicle CAD made in OnShape

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