This engine is designed to be tested on the Variable Engine Test Stand, utilizing nitrous oxide and isopropanol with an OF ratio of 4. The goal is to design an engine based on a chamber pressure of 300 psi and a thrust of 600 lbs at sea-level pressure. As a member of the engine team, I focused on nozzle design and interfacing with the chamber. The engine is ablative, and the nozzle material is graphite. As hot exhaust gases travel through the engine, the graphite erodes and removes some of the heat. 

When designing the first iteration of the nozzle, I decided to go with an 80% bell nozzle design, which would reduce the mass and manufacturing cost of the nozzle without greatly decreasing the thrust. Using engine design principles from Rocket Propulsion Elements, I created the nozzle contour, accounting for the diverging section's parabolic contour and a 45-degree contraction angle. To avoid fastening through graphite material, I designed the nozzle to be clamped into the chamber. 

In addition to modeling, I created the engineering drawing for the nozzle. I defined the tolerances and incorporated GD&T to prioritize certain dimensions and decrease the cost of manufacturing. 

After completing a preliminary design, I contacted graphite machining vendors with my CAD model and drawing to determine the cost of manufacturing the nozzle. However, the nozzle was determined to be too expensive to manufacture with graphite via vendors. The next step for the project is to redesign it as a heatsink engine and machine it at Boston University's manufacturing facility, EPIC.  

Redesigned Rocket Engine