Aerospace – one of the markets in which müller coax is active. German start-ups like the Augsburg-based Rocket Factory or HyImpulse rely on reliable coax® valve technology. As many can imagine, every little μ counts in this industry.
müller coax also collaborates on exciting projects as part of the support it provides to various research teams in this field, such as Space Team Aachen.
The STAHR (Space Team Aachen Hybrid Rocket) is the Space Team's latest project. Both the rocket and the test stand are outfitted with valves from müller co-ax ag.
Valves from müller coax provide the basis for multiple key functions of the propulsion system and the test stand. The Space Team decided to take advantage of coax – the pressure-relieved design allows for extremely rapid switching operations and allows for a high flow rate.
The heart of the rocket, its engine, has been developed and is being tested by the Space Team itself. It is a hybrid rocket engine configured such that the solid propellant (paraffin wax) is already located in the combustion chamber. The liquid oxidizer (nitrous oxide) is introduced via an injector and combusted with the solid propellant. Because nitrous oxide is only a liquid at room temperature and at a pressure exceeding 50 bar, it is pressurized and kept under pressure with an inert gas by means of a compressed gas delivery system.
To ensure a successful rocket launch and verify performance parameters such as thrust or regression rate, the engine is undergoing tests. The test stand, also a custom design by the Space Team, is equipped with coax valves.
For the test stand to function reliably, an oxidizer must be supplied to the combustion chamber via the main valve, a coax VMK 20. In order to provide the necessary mass flow for the engine, as much as of the substance as possible must flow through at once. This is exactly what the high Kv value of the coaxial valves ensures. The rapid and reproducible switching times of the coaxial valves ensure favorable timing for carrying out the ignition processes, thereby allowing the necessary flow rate to be achieved in good time. Additional externally controlled VMK 10 coaxial valves are used to supply compressed gas and provide pressure relief. A 3/2-way valve, the VMK 10 DR, which has two valve outputs for switching between the quenching and pressurization lines, is also installed in the test rig. For refueling the oxidizer tank, a VMK 10 valve is installed. It offers a high Kv value while ensuring low pressure losses. This allows large amounts of nitrous oxide to be transferred from the respective cylinder to the tank.