Phenomenology of plasma engine cathodes at high current rates and low pressures

The effects of low surrounding pressures on cathodes of arc jet engines with electromagnetic acceleration are investigated for pressure and current energies of 20 to 100 Torr. and 400 to 1000 A. Experiments with 50 mm long and 8 mm diameter tungsten-thorium cathode in a coaxial gas flow show that pre-heating of the cathode reduces the duration of the instable arc discharge and thus material loss. The use of lighter gases also reduces instability effects, as well as the use of increased pressures and a massive gas influx

Chemische Raketenantriebe - Motoren zum Zugang ins All. Experimentelle Untersuchung und Simulation von Brennkammervorgaengen

Chemical rocket engines as propulsion source of classic rocket launcher systems, from today's point of view, represent the most realistic and effective way for future launcher generations to meet future market requirements, i.e. to transport payloads into space at a calculable risk and at low cost due to their moderate complexity. The understanding of the essential internal engine processes - injection, processing, mixing, combustion - is key to a further increase in the reliability of propulsion by optimization. Some aspects of chemical rocket engines, namely hydrogen/oxygen high-pressure engines, are described in this paper. The tests involved are fundamental tests of model units. The corresponding research program of the German Aerospace Research Establishment, DLR, (HDR = high pressure rocket technology), under which the majority of investigations is funded, has a volume of DM 30 million over 5 years. DARA contributes another DM 3.2 million. (orig.)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman