基于近红外H2O的吸收光谱,开发了一种同时测量高速气流温度、速度及H2O摩尔分数等参数的方法并在超声速燃烧场中开展了应用研究,分析了超声速燃烧场中存在的现象及规律。基于扫描波长调制光谱技术,利用两条H2O吸收谱线在超燃直连台隔离段和扩张段中开展了实验研究,实现了多参数的同时测量。燃烧室点火后:隔离段内无激波时,气流速度、温度、压强和H2O摩尔分数测量值与预测值基本吻合,相对偏差分别小于3.0%、7.2%、8.2%和3.9%;有激波时,气体速度、温度、H2O摩尔分数和压力都发生了明显变化,空气质量流量均值变化不明显,但波动明显增大。实验结果表明,基于波长调制光谱的传感器具有重要的工程应用价值。

In this paper, a method of measuring gas temperature, velocity, and mole fraction of H₂O in a high-speed field based on near-infrared absorption spectra of H₂O is proposed. The method is applied to a supersonic combustion field and some phenomena and laws in the combustion field are analyzed. The experiment is performed in a scramjet isolation section and extended section based on wavelength modulation spectroscopy using two H₂O absorption spectral lines, and synchronous measurements of multiple parameters are realized. After performing the ignition test under combustion, the measured velocity, temperature, pressure, and mole fraction of H₂O are consistent with the predicted values when there is no shock wave in the isolation section, and the relative errors are less than 3.0%, 7.2%, 8.2%, and 3.9%, respectively. If the isolation section has a shock wave, the gas velocity, temperature, pressure, and mole fraction of H₂O have considerable differences. Additionally, information about the air mass flux has a small difference, but the fluctuation considerably increases. The experimental results show that the sensor based on wavelength modulation spectroscopy has great engineering value.