提出了基于波长调制光谱(WMS)方法实现非均匀燃烧场气体温度和H2O组分浓度场二维重建的测量方法。利用实验测得的2f/1f信号, 通过数值仿真与迭代实现了激光穿过非均匀燃烧场后积分吸光度的测量, 进而利用重建算法实现了燃烧场的二维分布测量。选用H2O的两组谱线对针对单高斯分布和阶跃分布模型开展了数值仿真研究, 并采用频分复用方法在平面燃烧火焰中开展了实验研究。结果表明：基于WMS方法的二维重建测量精度较高, 在单高斯分布模型中, 7185.60 cm-1和7454.45 cm-1谱线对的温度和H2O浓度的重建误差分别小于2%和2.5%; 在对温度敏感的区间内, 所选谱线对的重建误差较小, 在对温度不敏感的区间内, 重建误差较大; 火焰中心区域的重建结果与预测值一致, 温度重建误差小于3.2%, 在温度阶跃变化的边缘区域, 重建效果较差, 原因在于WMS方法和代数迭代算法对温度阶跃变化流场不敏感。

Measurement method of two-dimensional tomography of gas temperature and H2O concentration distributions in non-uniform combustion flow field is proposed based on wavelength modulation spectroscopy (WMS). By using the measured 2f/1f signals, we measure the integrated absorbance after laser passing through the non-uniform field according to numerical simulation and iteration. Then, we realize the measurement of two-dimensional tomography of combustion flow field using the reconstructed algorithm. The numerical simulation for single Gaussian and step change distribution models is carried out with selecting two groups of spectral lines of H2O. Frequency division multiplexing technology is adopted to realize the measurement of temperature and H2O concentration distributions in the flat combustion flame. It is proved that the method based WMS has relative high reconstruction accuracy. For single Gaussian model, the reconstruction errors of temperature and H2O concentration are less than 2% and 2.5% using the lines of 7185.60 cm-1 and 7454.45 cm-1. It also can be seen that the reconstruction errors are small if the lines are sensitivity to the temperature while the reconstruction errors are big if the lines are insensitivity to the temperature. Experimental results show that the reconstruction results are agreement with the predicted values in the middle region of flame where the temperature has the tendency of continuous change, the reconstruction error is less than 3.2%. However, in the edge region of flame where the temperature has the tendency of step change, the reconstructed effect is not good because the WMS and algebraic iterative reconstruction algorithm are insensitive to field where the temperature has the tendency of step change.