基于扫描波长调制光谱方法实现了超声速气流的温度、H2O组分浓度、压强、速度以及质量流量的测量。利用两条H2O吸收谱线的谐波信号，研究了均匀流场中超声速气流多参数同时测量的方法。基于波长调制光谱技术的测量结果能准确反映均匀流场中的气体参数，然而实际流场往往具有边界层。针对具有边界层的近似均匀流场，数值仿真研究了谱线选择和边界层厚度对流场中心流测量结果的影响。仿真结果表明，随着边界层厚度不断增大，测量结果误差逐渐增大，选择对边界层温度不灵敏的吸收谱线能够有效降低边界层的影响。对超燃直连台隔离段内的超声速气流进行实验研究，结果表明基于波长调制光谱的测量方法在强噪声和强振动的环境中具有较高的测量精度。温度、H2O组分浓度、压强、速度以及质量流量测量值与预测值的最大相对偏差分别在8.2%、7.2%、2.0%、3.1%和6.4%以内。

The temperature, H2O concentration, pressure, velocity and mass flux of supersonic gas flow are measured based on scanning wavelength-modulation spectroscopy method. The simultaneous measurement methods of multiple parameters of supersonic gas flow in uniform flow filed are studied using the harmonic signals of two H2O absorption spectral lines. The measurement results based on wavelength modulation spectrum technology can precisely reflect the gas parameters in the uniform flow field, while the actual flow field often has the boundary layers. Aiming at the approximate uniform flow field with boundary layer, the numerical simulation is carried out to study the effect of line selection and boundary layer thickness on the measurement result of core flow in flow field. The simulation results show that the measurement error increases with the boundary layer thickness, and the absorption spectral lines which are insensitive to temperature of boundary layers can effectively decrease the influence of boundary layer. The experiments of supersonic gas flow is carried out in a direct-connected scramjet test facility isolator, the results show that the measurement method based on wavelength modulation spectroscopy has high measurement accuracy in strong noise and strong vibration environments. The maximum relative deviation of predicted value and measured value for temperature, H2O concentration, pressure, velocity and mass flux are less than 8.2%, 7.2%, 2.0%, 3.1% and 6.4%, respectively.