基于相干反斯托克斯拉曼散射的二维温度场扫描测量

开展了基于相干反斯托克斯拉曼散射(CARS)技术的二维温度场扫描测量研究。通过同步扫描测量点及信号接收端的方式,实验测量了甲烷/空气预混火焰水平截面离散点的温度,并插值重建了二维温度场;用同步扫描法调节测量点与火焰的位置,实现了在扫描过程中对火焰同一空间位置的温度测量,排除了火焰空间分布不均匀性对扫描测温结果的附加影响。最后分析了提出的扫描CARS测量系统在实验设定状态下的扫描测温A类不确定度。结果显示:在扫描测量同一空间位置的实验中,测得该点平均温度为2 074K;测温A类不确定度优于21K。本研究量化了扫描CARS温度测量系统的不确定度,提高了扫描温度测量结果的可信度,为后续稳态火焰温度分布高精度测量、计算机流体动力学(CFD)模拟验证及燃烧基本问题研究奠定了实验基础。

2D scanning CARS for temperature distribution measurement

A 2D temperature field scanning measurement method in a combustion flow based on Coherent Anti-stokes Raman Scattering (CARS) was explored for temperature distribution measurements. By synchronized scanning incidence lasers and exit CARS signals, the temperatures of discrete points for methane/air premixed flame in a horizontal section were measured and a 2D temperature field was reconstructed by using 2D linear interpolation. The temperatures of the flame in the same space position in scanning processing was measured with synchronizing scanning method, by which the additional effect of flame space distribution in homogeneity on scanning measuring temperature was removed. Finally, the measuring uncertainty of the scanning CARS system was analyzed in a given experimental state. The experimental results for scanning measuring the same space position show the average temperature in the point is 2 074 K, meanwhile, the measuring uncertainty of the scanning CARS system is accounted below 21 K at the same experimental condition. In conclusion, the research quantizes the measuring uncertainty of the scanning CARS system, improves the reliability of results of scanning temperature measurement and provides an experimental foundation for the high precision measurement of flame temperature distribution, simulation validation of Computational Fluid Dynamics(CFD) and the investigation of flame problems.