What is PP ?
The goal of the propulsion team is to manufacture a hybrid motor which have the capability to send our rocket to an altitude of 10,000 ft (3048 meters), without blowing it up!
The main structure of the engine is made of the following sections, from top to bottom: The oxidizer tank, the injection valve, and finally the combustion chamber which holds the fuel. The engine also includes electronics: a card manufactured by the Avionics team which is optimized for the communication with this sub-system’s modules. Its main functions are to handle the ignition sequence, to command the main valve’s motor and to monitor the engine’s sensors.
The challenge is quite big; the thermal and mechanical stresses from whom this structure is subject require a meticulous process as for the calculations, design and tests of the engine’s parts.
We are currently searching for people with good knowledge about electronics/programming and material science.
How will it be implemented ?
Our combustion material’s choice has been focused on nitrous oxide (N2O, oxidizer) and a solid polymer (ABS, fuel). The advantage of the latter comes from the fact that it will be 3D printed, what offers the ability to play with some parameters (geometry, density) during the manufacturing process. On its side, the N2O is easy to use: stored in a standard bottle, the only step required is to transfer it into the engine’s tank. Its pressure, at a value of 55 bars, then allow to inject it into the combustion chamber without the need of an additional pressurization system.
To respond to the thermal stress existing in the combustion chamber, particular materials will have to be considered. These will form the isolating parts of the walls that will be exposed to the combustion reaction and the ones for the converging section of the nozzle.
Sensors to implement in the system will give a real-time measurement of the pressure and temperature inside the engine. Those information are crucial to give a GO/NO-GO from the propulsion system before the rocket’s launch occurs, especially during the competition who takes place in the desert near Las Cruces (New Mexico), where high temperatures are expected.
Finally, to develop and characterize our engine, it will be essential to test it on a test stand. A firing already happened with an engine bought by the EPFL Rocket Team, giving us some new experience about the process. The next one should happen soon!
We are currently searching for people with good knowledge of electronics/programming and material science.