| Project/Area Number |
13450398
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | Osaka University |
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Principal Investigator |
TAHARA Hirokazu Osaka University, Graduate School of Engineering Science, Associate Professor, 大学院・基礎工学研究科, 助教授 (20207210)
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| Co-Investigator(Kenkyū-buntansha) |
ONOE Ken-ichi Osaka University, Graduate School of Engineering Science, Assistant Professor, 大学院・基礎工学研究科, 助手 (70029429)
YOSHIKAWA Takao Osaka University, Graduate School of Engineering Science, Professor, 大学院・基礎工学研究科, 教授 (00029498)
安井 利明 大阪大学, 大学院・基礎工学研究科, 助手 (10263229)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥13,200,000 (Direct Cost: ¥13,200,000)
Fiscal Year 2002: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥9,300,000 (Direct Cost: ¥9,300,000)
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| Keywords | Arcjet Thruster / Space Propulsion / Electric Propulsion / Plasma Flow / Plasma Environment / Spacecraft Environment / Contamination / Plasma Diagnostics / プラズマプリューム / 直流放電 / 噴出流 / プラズマ・宇宙機干渉 |
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| Research Abstract |
Spectroscopic and electrostatic probe measurements were made to examine plasma characteristics with or without a titanium plate for a 10-kW-class direct-current arcjet thruster. Heat fluxes into the plate from the plasma were also evaluated with a Nickel slug and thermocouple arrangement. Ammonia and mixtures of nitrogen and hydrogen were used as a working gas. The NH_3 and N\2+3H_2 plasmas in the nozzle and in the downstream plume without a substrate plate were in thermodynamical nonequilibrium states. As a result, the H-atom electronic excitation temperature and the N_2 molecule-rotational excitation temperature intensively decreased downstream in the nozzle although the NH molecule-rotational excitation temperature did not show an axial decrease. Each temperature was kept in a small range in the plume without a substrate plate except for the NH rotational temperature for NH_3 working gas. On the other hand, as approaching the titanium plate, the thermodynamical nonequilibrium plasma came to be a temperature-equilibrium one because the plasma flow tended to stagnate in front of the plate. The electron temperature had a small radial variation near the plate. Both the electron number density and the heat flux decreased radially outward, and an increase in H_2 mole fraction raised them at a constant radial position. In cases with NH_3 and N_2+3H_2, a radical of NH with a radially wide distribution was considered to contribute to the better nitriding as a chemically active and non heating process.
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