ARC Control Experiments Using a High Performance ARC Heater
Final rept. 1 Sep 1980-30 Jun 1981
MCDONNELL DOUGLAS ASTRONAUTICS CO ST LOUIS MO
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Arc control parameters varied in these experiments were arc current, arc pressure, air flow rate, starting ramp rate, arc polarity, component resistance to ground, spin coil current, and gas injection distribution. Geometric parameters varied were nozzle throat area, constrictor length, and gas injection radius. Arc characteristics were documented on high-speed motion picture film at rates to 10,800 frames per second and by oscillograph. Analysis of these data indicated all of the parameters investigated had an effect on arc behavior and these effects are documented herein. The role of gas circulation and internal magnetic fields dominated other variations of the control parameters. Reduction of the nozzle throat area by a factor of two had a strong influence on the circulation level and arc instabilities resulted. Intersegment arcing was photographed at high frame rates as were other arc instabilities such as blow-through, roll-over, and kinking. Methods of improving the arc control and stability were identified and evaluated within the scope of the program. A total of 50 arc heater tests were made at arc currents to 830 A and pressures to 50 atm.
- Test Facilities, Equipment and Methods