Plasma Flow Structure of Direct-Current Arcjet Thrusters and Its Spacecraft Interaction Research

直流电弧喷射推进器等离子流结构及其与航天器相互作用研究

• 批准号: 13450398
• 负责人: TAHARA Hirokazu
• 金额: $ 8.45万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450398/
• 关键词: 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

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.

对一台10千瓦级直流电弧喷射发动机的等离子体特性进行了光谱和静电探针测量。从等离子体进入板中的热通量也用镍块和热电偶布置进行评估。氨以及氮气和氢气的混合物被用作工作气体。喷管内和下游羽流中的NH_3和N_2 +3H_2等离子体在无基片的情况下处于非平衡态。结果表明，虽然NH分子转动激发温度没有轴向降低，但H原子电子激发温度和N_2分子转动激发温度在喷管下游强烈降低。除NH_3工作气体的NH_4旋转温度外，在没有衬底板的情况下，羽流中的每个温度都保持在一个小范围内。另一方面，当接近钛板时，由于等离子体流在板前趋于停滞，因此等离子体的非平衡态变为温度平衡态。电子温度在平板附近有一个小的径向变化。电子数密度和热流密度均沿径向向外减小，而在一定径向位置上，随着H_2摩尔分数的增加，电子数密度和热流密度均增大。在NH_3和N_2+3H_2的情况下，NH自由基的径向分布较宽，是一种化学活性和非加热的渗氮过程。

项目成果

Hirokazu Tahara et al.: "Near Substrate Plasma Characteristics of a Supersonic Ammonia and Nitrogen/Hydrogen-Mixture DC Plasma Jet for Nitriding under a Low Pressure Environment"Proc. 15th Int. Symp. Plasma Chemistry. 1. 205-210 (2001)

Hirokazu Tahara 等人：“低压环境下用于氮化的超音速氨和氮/氢混合直流等离子体射流的近基底等离子体特性”Proc。

Hirokazu Tahara et al.: "Exhaust Plume Characteristics of Quasi-Steady MPD Thrusters"27th Int. Electric Propulsion Conf.. 1-9 (1999)

Hirokazu Tahara 等人：“准稳态 MPD 推进器的排气羽流特性”27th Int.

Hirokazu Tahara et al.: "Plasma and Heat Flux Characteristics of a Supersonic Ammonia or Nitrogen/Hydrogen-Mixture DC Plasma Jet"IEEE Trans. Plasma Science. 4(印刷中). (2003)

Hirokazu Tahara 等人：“超音速氨或氮/氢混合直流等离子体射流的等离子体和热通量特性”IEEE Trans 4（出版中）。

Hirokazu Tahara et al.: "Material Spraying Llsiing Electromagnetically Accelerated Plasma"Japanese Journal of Appl.Phys.. 4(印刷中). (2003)

Hirokazu Tahara 等人：“电磁加速等离子体材料喷射”，日本应用物理学杂志 4（印刷中）。

Hirokazu Tahara et al.: "Material Spraying Using Electromagnetically Accelerated Plasma"Jpn. J. Appl. Phys.. in press. (2002)

Hirokazu Tahara 等人：“使用电磁加速等离子体的材料喷涂”Jpn。