Tomographic laser absorption spectroscopy using Tikhonov regularization.
Tomographic laser absorption spectroscopy using Tikhonov regularization.
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DOI：
10.1364/ao.53.008095
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发表时间：
2014-08
期刊：
影响因子：
1.9
通讯作者：
A. Guha;I. Schoegl
中科院分区：
文献类型：
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作者：
A. Guha;I. Schoegl
可调谐半导体激光吸收光谱（TDLAS）技术在火焰温度场和浓度场非均匀性研究中的应用是一个研究较少的领域。实验工作探讨了层析重建的性能，从波长调制的TDLAS测量内的轴对称麦肯纳燃烧器的羽流的物种浓度和温度分布。水蒸气跃迁在1391.67和1442.67 nm的探测使用校准的无波长调制光谱与二次谐波检测（WMS-2f）。单个准直激光束平行于燃烧器表面扫描，其中扫描在多个径向位置产生成对的视线（LOS）数据。使用Tikhonov正则化Abel反演，它抑制了通常观察到的高空间分辨率重建的实验噪声的放大，重建的吸收数据的径向轮廓。基于光谱数据重建，逐点计算温度和摩尔分数。在这里，最小二乘方法解决了由于调制深度的困难，由于不均匀的域不能普遍优化。实验结果表明，成功的重建的温度和摩尔分数分布的基础上，两个过渡，非最佳调制WMS-2f和Tikhonov正则化阿贝尔反演，从而验证了该技术作为一个可行的诊断工具火焰测量。
The application of tunable diode laser absorption spectroscopy (TDLAS) to flames with nonhomogeneous temperature and concentration fields is an area where only few studies exist. Experimental work explores the performance of tomographic reconstructions of species concentration and temperature profiles from wavelength-modulated TDLAS measurements within the plume of an axisymmetric McKenna burner. Water vapor transitions at 1391.67 and 1442.67 nm are probed using calibration-free wavelength modulation spectroscopy with second harmonic detection (WMS-2f). A single collimated laser beam is swept parallel to the burner surface, where scans yield pairs of line-of-sight (LOS) data at multiple radial locations. Radial profiles of absorption data are reconstructed using Tikhonov regularized Abel inversion, which suppresses the amplification of experimental noise that is typically observed for reconstructions with high spatial resolution. Based on spectral data reconstructions, temperatures and mole fractions are calculated point-by-point. Here, a least-squares approach addresses difficulties due to modulation depths that cannot be universally optimized due to a nonuniform domain. Experimental results show successful reconstructions of temperature and mole fraction profiles based on two-transition, nonoptimally modulated WMS-2f and Tikhonov regularized Abel inversion, and thus validate the technique as a viable diagnostic tool for flame measurements.