摘要
气体流速的测量对于航空航天发动机的燃烧诊断等应用非常重要。针对现有可调谐激光吸收光谱测量方法的不足,提出基于波长调制光谱二次谐波归一化四次谐波（WMS-4f/2f）的检测方案。不同于目前采用的直接吸收光谱或波长调制光谱二次谐波检测方法,WMS-4f/2f方案可以得到更尖更窄的吸收峰,有利于更精准地确定多普勒频移。对此方法测量流速的不确定度进行了理论分析和数值仿真,结果表明,选用O2位于760.445nm的吸收线,所得气体流速不确定度为5.66m/s,与WMS-2f或直接吸收光谱方法相比不确定度降低了一个数量级。该方法在高速流场的流速测量领域具有巨大的应用潜力。
Gas flow velocity is a very important parameter in the combustion diagnosis for aerospace engines.Wavelength modulation spectroscopy 4 f harmonic signal detection normalized by 2 f harmonic signal（ WMS-4 f/2 f） scheme was proposed for overcoming disadvantages of current measurement methods by tunable diode laser absorption spectroscopy.Different from the traditional methods of WMS-2 f and direct absorption spectroscopy,WMS-4 f/2 f scheme can obtain sharper and narrower absorption peaks,which can be used to determine the Doppler shift more precisely. The uncertainty of this method for measuring velocity is analyzed and simulated. By using an O2 absorption line located at760. 445 nm,the measurement uncertainty of gas flow is 5. 66 m/s,one order of magnitude reducing compared to the WMS-2 f measurement. This method has great potential for the application of gas velocity measurement in high speed flow field.
作者
陈佳音
李金义
李浩丹
马帅
李雨璇
CHEN Jiayin;LI Jinyi;LI Haodan;MA Shuai;LI Yuxuan(Tianjin Polytechnic University,Tianjin 300387,China)
出处
《激光杂志》
北大核心
2018年第8期15-19,共5页
Laser Journal
基金
国家自然科学基金项目(No.61505142)
天津市自然科学基金项目(No.16JCQNJC02100,No.17JCYBJC16800)
天津市教委科研计划项目(No.2017KJ085)
关键词
波长调制光谱
高次谐波探测
多普勒频移
流速测量
不确定度
wavelength modulation spectroscopy
high- order harmonic detection
doppler shift
velocity measurement
uncertainty
