Test Analysis of C/C-SIC Combustion Chamber for Nitrous Oxide//Ethane 22N Thruster

Kurzfassung

Within DLR interdisciplinary project Neo Fuels the DLR Institute of Space Propulsion and DLR Institute of Structures and Design are investigating fibre-reinforced ceramics as thrust chamber material for the use in space propulsion applications.16 A 22 N-class thruster made from C/C-SiC has been designed, manufactured and tested. A nitrous oxide/ethane-based bipropellant is used as alternative propellant for the highly toxic hydrazine-based state-of-the-art systems. The hot fire test campaign with nitrous oxide/ethane and near vacuum conditions was conducted at DLR Lampoldshausen M11 testing facility. Six different thrust chambers were tested. Firing time was increased from 1s to 1 minute to get information on the durability of the C/C-SiC materials. A maximum cumulative firing time of 644 s was achieved, before failure of the chamber. C* combustion efficiency in the range of 55 - 92% was observed. To quantify temperatures, the thrust chamber wall was monitored via a thermocouple and an infrared camera, resulting in measured maximum wall temperatures far above 1000C. Infrared camera recordings visualize the temperature distribution along the chamber and nozzle wall, showing hot spots from the injector.