This thesis follows the design and testing of the combustion chamber and nozzle of a Mach 2, liquid fuelled free-flying Ramjet. This combustion chamber and nozzle design includes specification of critical dimensions required in order to achieve the desired performance, along with material selection and an investigation into the performance of the chosen fuel to be used with the ignition system design. These systems will then be integrated with those designed in two other undergraduate theses to give the complete design specifications for the ramjet.
The ramjet was flight tested in October at the Australian Space research Institute launch facility at Woomera in South Australia. It was launched as the payload on a Zuni rocket. This is capable of accelerating the ramjet to Mach 2 in approximately one second. After this time, the ramjet will separate from the Zuni and continue to cruise at Mach 2 for approximately three seconds.
While the ramjet was designed to be a free-flyer, time restrictions meant that the design had to be modified in order meet the launch deadline. An electrical fault that occurred the night before launch meant that the ignition system had to be removed from the assembly with the hope of achieving autoignition. The electrical fault also damaged the accelerometer and most of the pressure sensors. For unknown reasons the thermocouple was also damaged. The only useful data retrieved during the flight was fuel pressure and altitude.
While the overall project was regarded a failure, the combustion chamber was not properly tested and therefore may still be a successful design. In order to confirm this, this design will need to be implemented with a functional ignition system and flight tested once more.
The recommendations given discuss concerns with the combustion chamber design and suggest possible modifications, however without having properly testing the combustion chamber no design alterations are evident. The recommendations also suggest modifications that may prevent the failure of future designs based on the reasons that this project was not successful. With these design modifications, it is expected that a successful Mach 2, free-flying ramjet will be launched within the next few years.