Hybrid Parabolic Rocket Nozzle

Outcome & Impact

As my first project with BURPG in Fall 2024, I led a five-person team to design, optimize, and physically hotfire a theoretical 7.86 lbf thrust hybrid rocket nozzle. We optimized the nozzle for 45,000 ft, successfully reducing the mass by 73% and increasing thrust by 5%. The system was fully validated structurally during a successful 2-second live hotfire test.

Experience & Skills

Role: Overall and Design Lead

I directed the project through three iterative design reviews, coordinating the subteams responsible for the test fire computer, engineering drawings, and FEA. To mitigate early-undergrad procrastination, I managed cross-team communication and enforced a system of soft and hard deadlines.

• Nozzle Design & CAD: Modeled an 80% parabolic de Laval nozzle in SolidWorks. Mapped a Bezier curve across three points for the diverging section and used circular curves for the converging and throat sections, strictly following G.V.R. Rao’s optimization methods.
• FEA & Structural Optimization: Validated the system using SolidWorks FEA, which I learned and troubleshooted from scratch. Initially optimized the contour to a 2.0 FOS to aggressively cut weight, but after a design review flagged handling concerns, I thickened the geometry to a final 7.8 FOS in yield.
• Manufacturing: The nozzle was manufactured using a Formlabs SLA printer in ABS resin, intended for a single-use hotfire.

Testing & Validation

Hotfire & Data Acquisition: The system was successfully fired for a 2-second burn. We integrated a LabJack DAQ system and a load cell to capture thrust data. Unfortunately, the load cell broke prior to data collection—a valuable, hands-on lesson in the importance of hardware redundancy and pre-test sensor validation.

Motivation & Constraints

Objective: The Hybrid Introductory Project (HIP) is BURPG's hands-on trial for new members to learn compressible flow, nozzle design, and FEA. The goal was to calculate, design, and build a nozzle and test computer that maximized thrust and minimized weight.

• Optimization Target: 45,000 feet
• Design Constraints: Strict parameters for optimization pressure, mass flow rate, and maximum diameter.