基于滤波反投影算法的TDLAS温度测量研究

TDLAS Temperature Measurement Based on Filtered Back Projection Algorithm

关键词:  滤波反投影算法  TDLAS  重建温度场  重建质量  噪声影响

Key words:  Filtered back projection algorithm  TDLAS  Reconstruction temperature filed  Reconstruction quality  Noise influence

摘要:

为提高二维重建温度场的抗噪声、抗干扰能力，研究了基于滤波反投影算法的可调节半导体激光吸收光谱（TDLAS）系统。通过数值模拟研究了滤波反投影算法的重建质量与影响因素，结果表明，随机噪声达到10%时，重建图像仍能较好地反映原温度场特征；滤波函数能明显改善重建质量；三次样条曲线插值的重建质量最高。通过基于滤波反投影算法的 TDLAS系统对弱旋流燃烧室出口温度场进行重建，将重建结果与热电偶测量结果进行对比，相对误差范围为1.4%～8.9%，较好地反映出温度场的特征，验证了滤波反投影算法的层析成像系统的可行性。

Abstract:

In order to improve the anti-noise and anti-interference ability of the two-dimensional reconstruction temperature field， this paper studies the tunable diode laser absorption spectroscopy （TDLAS） system based on filter back projection algorithm. First， through numerical simulation， reconstruction quality and influence factors of the filtered back projection algorithm are studied. The results show that when the random noise reaches 10%， the reconstructed image can still reflect the original temperature field characteristics. Filtering functions can significantly improve the reconstruction quality. The cubic spline curve interpolation has the highest reconstruction quality. Second， the temperature field at the outlet of the low swirl burner was reconstructed by the TDLAS system. Reconstruction results were compared with the thermocouples results. The relative error range is 1.4%～8.9%， which reflects the characteristics of temperature field well， the feasibility of the tomography system based on filter back projection algorithm is proved.