Hybrid 2026

This is our final year engineering project. This is a temporary repository to provide some info until we add full project details to the main repo.

This is a UC Aerospace club project. The aim is to develop a flight ready hybrid rocket engine that can be flown in IREC. This hybrid engine uses a solid ABS fuel grain with N₂O oxidiser. This year we are building on work completed in previous years. The project includes a mechanical team for development of the physical engine components, and a mechatronics team for development of the associated electronic control systems.

Mechatronics team

The tron team goals consist of:

• Development of flight ready engine control unit (ECU)
• Development of wireless telemetry and control system
• Development of remote automatic fill station for the nitrous flight tank

My part in the project has mostly involved working on the ECU. This is the main electronic system that runs the engine. The ECU consists of a custom PCB and accompanying sensors & valves. The design is heavily based on work completed for last year's test stand project.

The ECU includes the following features:

• High performance STM32H5 MCU
• 256 MB NAND flash chip for data logging
• USB for debugging and/or data extraction
• FD-CAN transceiver for communication with other modules (radio, recovery, etc.)
• RS-422 transceiver for communication with ground/fill station
• Secondary (higher voltage) power supply and circuitry to control:
  • Ematch ignitors
  • 2x solenoids (main oxidiser and vent valves)
  • Servo motor
• Battery voltage monitor
• 5x thermocouple ports (read using dedicated ADC chip)
• 3x thermistor ports for thermocouple cold junction compensation
• 4x inputs for ratiometric pressure sensor. Manifold, combustion chamber, tank lower and tank upper.

At the time of writing, the new PCB is almost complete. The new software has not been started, but the team last year made a significant effort and much of it can be copied over.

The main challenge with this project is figuring out what can be copied over, and this applies to the PCB as well. There are so many variables, and it's been tough (for me) to actually manage the massive list of requirements. It is often hard to sort through the many possible ways to solve a problem and just make a decision. Limited budget was also something we faced this year, many decisions were made to try and minimize costs where possible.

Mechanical team

The mechanical team is responsible for the engine hardware. This includes designing new components and improving existing components (from last year) via simulations. These components include:

• Nozzle
• Mixing diaphragm
• Combustion chamber
• Bulkhead
• Injector & manifold
• Flight oxidiser tank (new)
• Engine to tank interface & valve (new)
• Tank venting system (new)