A new technique is developed for reconstructing the temperature and species-concentration fields by employing tunable diode laser absorption spectroscopy (TDLAS) and laser-induced breakdown spectroscopy (LIBS) on axisymmetric combustion fields. For two-line thermometry, the uncertainties in linestrengths of the absorption lines may cause systematic errors in temperature and species concentration estimations. Thus, the radial profiles of water vapor concentration are obtained first using the LIBS, assuming that the combustion is complete; then, the radial temperature profiles are estimated from the radial profiles of absorption coefficient, as reconstructed from the absorbance profiles obtained using the TDLAS. The spectral lines of water vapor at 7185.6 and 7444.36 cm⁻¹ are selected as the linestrengths show monotonic decreases with the increase in temperature within the measuring temperature range. The radial profiles of temperature and water mole fraction are well-reconstructed, and the measurement error is found to be as low as 3%. The technique yielded higher temperatures compared to the thermocouple, possibly owing to the significant radiative heat loss in the thermocouple data.

中文翻译：

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结合使用TDLAS和LIBS重建温度和浓度场。

通过在轴对称燃烧场上采用可调二极管激光吸收光谱（TDLAS）和激光诱导击穿光谱（LIBS），开发了一种用于重构温度和物种浓度场的新技术。对于两线测温法，吸收线的线强度的不确定性可能会导致温度和物质浓度估计的系统误差。因此，假设燃烧已完成，首先使用LIBS获得水蒸气浓度的径向分布图；然后，再进行燃烧。然后，根据使用TDLAS获得的吸光度分布图重建的吸收系数的径向分布图估算径向温度分布图。水蒸气的光谱线在7185.6和7444.36 cm ^-1选择线强度是因为在测量温度范围内，线强度随温度的升高而单调降低。温度和水摩尔分数的径向分布被很好地重构，并且发现测量误差低至3％。与热电偶相比，该技术产生的温度更高，这可能是由于热电偶数据中的大量辐射热损失所致。