M1 is our first rocket motor prototype. It will allow us to carry out experiments to design future rockets later on. It will serve us to compare fuels and to choose the most suitable for efficient propulsion.
When performing the experiments we will face the following problem: the flow of the oxidant is not constant. This is due to the pressure drop in the oxidant container as it is emptied. The combustion pressure also varies as the ignition progresses. The solution is to add an injector which we have designed to make it sure that our oxidant (nitrous oxide in its gas phase), which is at a pressure of 40 bars, has a constant flow of 0.15 kg/s.
The injector throttles the flow causing it to exit at sonic speed. This makes the flow rate constant and it loses the dependency downstream, only depending on the upstream pressure.
The injector together with the holder has to support up to 2 tons of force and its designs have to be made with this in mind. The material we have chosen is aluminum 6064 T6 because it is a light material and it is representative of a real engine, with which we are getting experience for the future. Its low resistance to temperature can be solved by adding a protective layer of ceramic insulators on the faces in contact with the gases, which are more than 1500 ºC. In addition, one of our needs is to assemble and disassemble the piece without damaging it, for which we have introduced
Thanks to the CFAA we have met our design specifications for the injector and the holder. The CFFA has been in charge of the machining, in a multitasking machine, of the two pieces.