航空学报 > 2019, Vol. 40 Issue (8): 122841-122841   doi: 10.7527/S1000-6893.2019.22841

基于TDLAS的电弧风洞流场Cu组分监测

陈卫, 伍越, 黄祯君, 王磊, 袁竭, 胡江华, 王茂刚, 朱涛   

  1. 中国空气动力研究与发展中心 超高速空气动力研究所, 绵阳 621000
  • 收稿日期:2018-12-10 修回日期:2019-03-13 出版日期:2019-08-15 发布日期:2019-04-01
  • 通讯作者: 伍越 E-mail:wuyue_cardc@163.com
  • 基金资助:
    国家自然科学基金(11702312)

Monitoring copper species in flow of arc-heated wind tunnel based on TDLAS

CHEN Wei, WU Yue, HUANG Zhenjun, WANG Lei, YUAN Jie, HU Jianghua, WANG Maogang, ZHU Tao   

  1. Hypervelocity Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China
  • Received:2018-12-10 Revised:2019-03-13 Online:2019-08-15 Published:2019-04-01
  • Supported by:
    National Natural Science Foundation of China (11702312)

摘要: 电弧风洞是进行防热材料和防热结构考核与研究的必要设备,也是高超声速地面试验能力的重要组成部分,但电弧加热器的电极烧蚀会导致较为严重的流场污染,影响试验准确性。利用可调谐二极管激光吸收光谱技术(TDLAS),通过对20 MW级片式电弧加热器内部流场中Cu原子809.25 nm跃迁谱线进行实时测量,研究了电弧风洞流场中Cu污染情况和电极烧蚀情况。在获得Cu原子该谱线低能态数密度基础上,估算了运行功率分别在7.3、8.7、10.0和11.7 MW时流场中Cu组分(原子态和离子态)总数密度平均为10.6×1013、11.2×1013、11.7×1013和16.4×1013 cm-3,同时得到平均电极烧蚀率约为1.65×10-5 g/C。试验还发现,TDLAS信号在高温流场建立阶段起伏变化明显,并且在功率跃变时也会出现突然增强而后迅速回落的现象,表明电弧抖动会使电极烧蚀严重加剧。

关键词: 电弧风洞, 可调谐二极管激光吸收光谱技术(TDLAS), 流场污染, 电极烧蚀, Cu原子

Abstract: Arc-heated wind tunnel, as an important hypersonic test facility, is indispensable for examining and developing thermal protection materials and structures. However, the flow is always contaminated by copper species generated from the surface molten or boiled electrodes, undermining the accuracy of the experiment. In this work, to quantitatively study the copper contamination and the electrode ablation, the Tunable Diode Laser Absorption Spectroscopy (TDLAS) is employed by measuring the 809.25 nm transition spectrum line of Cu in real-time in the 20 MW segmented arc heater. Based on acquisition of the number densities of lower state, the average number densities of copper species (including atoms and ions) in the inner flow of arc heater with the different power of 7.3, 8.7, 10.0 and 11.7 MW are measured, deriving results as 10.6×1013, 11.2×1013, 11.7×1013, and 16.4×1013 cm-3 respectively. In the meantime, the average electrode ablation rate (defined by mass loss per unit of charge crossing the electrode surface) is obtained as about 1.65×10-5 g/C. What's more, the monitoring TDLAS signal showed violent fluctuation before the steady flow is established and showed sudden sharp rise when the power of the arc heater changed, demonstrating that the fluctuation of arc spots could greatly aggravate the electrode ablation.

Key words: arc-heated wind tunnel, Tunable Diode Laser Absorption Spectroscopy (TDLAS), flow contamination, electrode ablation, copper atom

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