光线分布对基于TDLAS温度场二维重建的影响

基于可调谐半导体激光吸收光谱（TDLAS）技术采用代数迭代算法实现燃烧场温度二维重建。在有限入射光线数目下为获得最佳重建结果，研究了扇形光束和平行光束分布下光线数目、网格数目对温度场重建结果的影响规律。提出虚拟光线方法，通过在相邻光线间增加虚拟光线，减小网格间距以增加网格数目，满足在光线数目较少情况下，实现了较为细致的二维温度场重建。计算结果表明当光线间距与网格间距比在0.6~1范围内时，重建温度场相对均方误差最小。在相同入射光线数目情况下，虚拟光线法可以有效降低重建温度场相对均方误差，提高重建二维温度场精确度。

Influence of beam distribution on two-dimensional temperature field reconstruction using TDLAS

Based on tunable diode laser absorption spectroscopy technique, two-dimensional temperature field in combustion was reconstructed using modified adaptive algebraic reconstruction technique (ART). Aimed at achieving an optimal reconstruction result with limited number of beams, the influence of the beam parameters and grid number on temperature field reconstruction was investigated. A virtual beam method with virtual beams added adjacent two beams and an increased number of grids was developed to describe the reconstructed temperature field in detail when the number of beams was limited. The simulation results indicate that the normalized mean absolute error is low when the ratio of beam spacing to the grid spacing was between 0.6 and 1. Compared with other methods, the normalized mean absolute error is significantly reduced using the virtual beam method.