实验流体力学Issue(3)：62-67,6.DOI:10.11729/syltlx20140071
电弧风洞中基于TDLAS的气体温度和氧原子浓度测试
Measurements of gas temperature and atomic oxygen density in the arc-heated wind tunnel based on TDLAS
欧东斌 1陈连忠 1董永晖 1林鑫 1李飞 2余西龙2
作者信息
- 1. 中国航天空气动力技术研究院，北京 100074
- 2. 中国科学院力学研究所 高温气体动力学国家重点实验室，北京 100190
- 折叠
摘要
Abstract
Large-scale,high-enthalpy arc heated wind tunnels are the most reliable ground test facilities to test thermal protection materials and heat shield structures for space vehicles. Flow conditions in the facility need to be monitored.Currently,the facility conditions are defined using either the anticipated surface temperature with an assuming emissivity or the expected heat flux level.While this is useful to evaluate relative performance of the facility,it is not sufficient for quantitative measurement of the flow conditions.Temperature is one of the most important thermodynamic quantities in determining arc heated wind tunnel because it is a key parameter in determining arc-heater operating status and chemical reactions.Therefore,the development of accurate quantitative diagnostic techniques is necessary for better understanding the complex physics involved in the arc heated wind tunnel.The design of a tunable diode laser absorption spectroscopy (TDLAS)system to probe gas parameters during a bow shock wave ahead of a wa-ter cooled copper cylinder is presented in this paper.TDLAS is an effective method for measuring gas temperature and concentration in many fields due to its advantage of non-intrusive,high sensitivity, gas-specific and quick response.In our studies,an atomic oxygen absorption line near 777.2nm is utilized for detecting the arc-heated plasma using scanned-wavelength direct absorption mode with 100Hz repetition rate.The value of temperature is inferred directly from the Doppler broadening component of the absorption lineshape.Moreover,the number density of atomic oxygen is also determined through the integrated absorbance assuming local thermal equilibrium conditions. The agreement of the experimental observations and theoretical calculations shows that the ther-mal equilibrium assumption is valid.The current experimental results of this study illustrate the high potential of TDLAS measurements for routine and economical monitoring of arc heated wind tunnel operating status (gas temperature)as well as the time-resolved flow conditions in front of the model.关键词
TDLAS/电弧风洞/流场参数/气体温度/氧原子浓度Key words
Tunable Ddiode Laser Absorption Spectroscopy (TDLAS)/arc heated wind tun-nel/flowfield parameter/gas temperature/number density of atomic Oxygen分类
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欧东斌,陈连忠,董永晖,林鑫,李飞,余西龙..电弧风洞中基于TDLAS的气体温度和氧原子浓度测试[J].实验流体力学,2015,(3):62-67,6.
