Endurance testing of the additively manufactured STAR resistojet
| Autor: | Angelo Grubisic, Christopher Ogunlesi, Matthew David Robinson, G. Rempelos, S. Ahmed, Federico Romei |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Spacecraft business.industry Mechanical Engineering Nuclear engineering 02 engineering and technology Concentric Propulsion 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Mechanics of Materials Heat exchanger Regenerative heat exchanger lcsh:TA401-492 lcsh:Materials of engineering and construction. Mechanics of materials General Materials Science Endurance testing Selective laser melting 0210 nano-technology Joule heating business |
| Zdroj: | Materials & Design, Vol 180, Iss, Pp-(2019) |
| ISSN: | 0264-1275 |
| Popis: | This paper reports the outcome of endurance tests performed on a proof-of-concept design of a high-temperature resistojet thruster. A high-performance resistojet could enable a fully all-electric spacecraft architecture providing all propulsion system functions. The thruster utilises a novel additive-manufactured heat exchanger, consisting of concentric thin-walled cylinders, which act as both a resistive heating element and regenerative heat exchanger. Two complete thruster assemblies were tested, with heat exchangers manufactured from 316L stainless steel using selective laser melting. The two test units were used to investigate the operational endurance and determine life-limiting failure modes of the design. The tests consisted of repeated operational cycling to known temperature limits while under vacuum. Degradation and failure was inferred from electrical characteristics of the thrusters, and X-ray computed tomography imaging was used for non-destructive inspection both pre- and post-testing. The analysis showed that the failure modes are due to thermally-induced stresses resulting from mechanical constraints and temperature gradients. The failures occurred after approximately 40 cycles in the first thruster operating with a current of 25 A, and, in the second thruster, after a total of 300 cycles at 15 A and 217 cycles at 20 A, resulting in two distinctly different failure locations. Keywords: Resistojet, Spacecraft propulsion, Additive manufacturing, X-ray CT, All-electric spacecraft, Endurance testing |
| Databáze: | OpenAIRE |
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