Low power dc arcjet operation with hydrogen/nitrogen propellant mixturesThe arcjet assembly from a flight model system was modified with a new thoriated tungsten nozzle insert and has been tested with hydrogen-nitrogen mixtures simulating the decomposition products of ammonia and hygrazine. Arcjet power consumption ranged from 0.7 to 1.15 kW depending on low rate, input current, and mixture composition. At a nominal 1 kW power level the ammonia mixtures thrust efficiency was about 0.31 at specific impulse values ranging between 460 and 500 sec. Hydrazine mixtures gave similar thrust efficiencies at the same power level with specific impulse values between 395 and 430 sec. Large, spontaneous voltage mode changes were not observed once the thruster had passed a period of instability immediately following start up. This period of instability, and the startup at low pressure, were seen as major causes of constrictor damage during the tests.
Document ID
19860057938
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Curran, F. M. (NASA Lewis Research Center Cleveland, OH, United States)
Nakanishi, S. (NASA Lewis Research Center; Analex Corp. Cleveland, OH, United States)