Air-Augmented Hybrid Rocket System

Special thanks to Dr. Stephen Whitmore, PhD

Project Description

Typical rocket systems are constrained by the amount of oxidizer and fuel they can carry. The air-augmented system would use air as a free oxidizer to allow for combustion while using less on-board oxidizer. Our project objective was to create a hybrid rocket system that could be augmented by air to provide enough thrust to help offset drag and effectively increase the range of the system.
Project Constraints
- No complex mechanical designs
- Thrust from air-augmentation cannot be negligible
Project Requirements
- System can throttle oxidizer flow to 25% and back up to 100%
- Prototype must maintain thrust during combustion by increasing pressure to the choking mass flow rate at the throat and not at the injector
- The throttling valve must throttle in a near-linear fashion
- The system should ignite with no less than 80% reliability

Extensive testing resulted in data from the venturi, the injector, and the nozzle
All testing was done in the USU test cell and all safety precautions were taken
Testing ensured shockwaves were not present at optimal operating pressure
The team used thermocouples, pressure transducers, load cells, and a venturi to obtain data at multiple points throughout the system to determine the performance of the design

The design successfully met all requirements and constraints designated by the customer
The team learned about the linearity of different ball valves, how to optimize a rocket motor, how to utilize different instrumentation, and the importance of communication with the customer and clearly defining expectations
The team recommends that for future work the valve be upgraded to allow for more precise throttling and using a more realistic oxidizer in testing